Well-defined palladium–gold nanoparticles (PdAuNPs) with randomly alloyed structures and broadly tunable compositions were studied in catalytic nitrite (NO2–) reduction. The catalysts were synthesized using a microwave-assisted polyol coreduction method. PdxAu100–xNPs with systematically varied compositions (x = 18–83) were supported on amorphous silica (SiO2) and studied as model catalysts for aqueous NO2– reduction in a batch reactor, using H2 as the electron donor. The reactions followed pseudo-first-order kinetics for ≥80% NO2– conversion. The PdxAu100–xNP-SiO2 catalysts showed a volcano-like correlation between NO2– reduction activity and x; the highest activity was observed for Pd53Au47, with an associated first-order rate constant of 5.12 L min–1 gmetal–1. Alloy NPs with greater proportions of Au were found to reduce the loss in catalytic activity due to sulfide fouling. Density functional theory calculations indicate that this is because Au weakens sulfur binding at PdAuNP surfaces due to atomic ensemble, electronic, and strain effects and thus reduces sulfur poisoning. The environmental relevance of the most active supported catalyst was evaluated by subjecting it to five cycles of catalytic NO2– reduction. The catalytic activity decreased over multiple cycles, but analysis of the postreaction PdxAu100–xNP-SiO2 materials using complementary techniques indicated that there were no significant structural changes. Most importantly, we show that PdxAu100–xNP-SiO2 alloys are significantly more active NO2– reduction catalysts in comparison to pure Pd catalysts.Keywords: density functional theory (DFT); heterogeneous catalysis; microwave synthesis; nitrite hydrogenation; palladium−gold alloys; sulfide poisoning; water treatment;

•A unique family of lanthanide-based solid-state sensors has been prepared•The sensors can detect trace H2O in D2O from 10 to 120,000 ppm•The sensors can rapidly identify unknown solvents•The sensors can quantitatively detect trace H2O in organic solventsDeuterium oxide or heavy water (D2O) is an isotopically labeled version of regular water (H2O) and is vital for a wide range of applications, including chemical analysis and medicine. However, because it is almost identical in size and shape to regular water, discrimination between these two water variants is tremendously difficult. Currently, only cumbersome laser-based methods are able to detect low levels of H2O contamination in D2O. No convenient technology allows the rapid, point-of-need sensing of trace water in D2O. Here, we report on a solution to this unsolved problem.Our solution relies on a unique family of luminescent materials. These lanthanide-based systems function as highly accurate solid-state sensors that can quantitatively detect H2O in D2O from 10 to 120,000 ppm. These sensors can also detect trace H2O in a variety of common solvents that typically present problems for conventional sensing methods, such as Karl-Fischer analysis.PCM-22, a metal-organic framework material comprising triphenylphosphine and Ln3+ ions (Ln = Pr–Yb), exhibits solid-state luminescence at room temperature. Mixed-metal versions of PCM-22 that contain controlled amounts of Eu3+, Gd3+, and Tb3+ function as highly sensitive, broad-scope solid-state sensors that can rapidly identify unknown solvents by providing a unique “eight-factor” fingerprint. The sensors allow for immediate solvent identification via color changes that are obvious to the naked eye and also permit quantitative chemical analysis by uncomplicated spectrophotometry. These same materials achieve quantitative detection of H2O in D2O from 10 to 120,000 ppm. The detection of trace H2O is also demonstrated in a range of common solvents, including those incompatible with conventional laboratory titration methods.Download high-res image (190KB)Download full-size image

Mesoporous LaMnO3 with bulk surface areas in the range 225–300 m2 g−1 were prepared by direct overgrowth around the short-channel version of SBA-15 silica. The extent of LaMnO3 growth was found to be affected by the polarity of solvent system used to impregnate the SBA-15 with La3+ and Mn2+ precursors. The resulting LaMnO3–SiO2 composites were stable in refluxing NaOH, suggesting that the SiO2 was fully encapsulated. The composites were structurally characterized using a range of techniques including 2-D elemental mapping and Raman spectroscopy. The electrochemical behavior of the composites was tested for pseudocapacitance, which revealed normalized specific capacitances over 200 F g−1.

High quality crystalline Co-CUK-1 can be synthesized rapidly and efficiently by a microwave-assisted method. The resulting microporous coordination material is a highly effective adsorbent for the separation of xylene isomers and ethylbenzene, as demonstrated here through sorption isotherm analysis, Ideal Adsorbed Solution Theory (IAST) calculations, and grand canonical Monte Carlo (GCMC) simulations. Co-CUK-1 showed high sorption capacity and high adsorption selectivity for p-xylene over the corresponding m- and o-isomers, and ethylbenzenes. According to the data obtained from IAST and GCMC simulations, the Co-CUK-1 is found to strongly favour p-xylene adsorption because p-xylene molecules undergo well-defined molecular packing in the 1-D channels; by comparison, the packing efficiencies of o-xylene, m-xylene and ethylbenzene are significantly lower, as is evidenced by lower saturation capacities.

PdxAu100–x nanoparticle (NP) catalysts with well-defined morphologies and compositions can be rapidly prepared using a simple microwave-assisted synthetic approach. Common Pd(II) and Au(III) precursors are coreduced in ethylene glycol to give small and nearly monodisperse (2.5 ± 0.6 nm) NPs with homogeneously alloyed structures in less than 300 s at 150 °C. A comparison of the nucleation and growth processes responsible for the formation of PdAuNPs by microwave and conventional methods revealed faster and more reproducible product formation under microwave-assisted heating. Pd-rich NPs were rapidly formed, into which Au atoms were subsequently incorporated to give the alloyed NPs. The value of x in the PdxAu100–xNPs obtained can be finely controlled, allowing the surface electronic structure of the NPs to be broadly tuned. This permits model heterogeneous reaction studies, in which catalytic reactivity can be directly related to Pd:Au composition. Vapor-phase alkene hydrogenation studies using a series of PdAuNPs with varying compositions revealed that Pd59Au41NPs were catalytically the most active. Detailed theoretical studies of the entire hydrogenation reaction catalyzed at randomly alloyed PdAu surfaces were performed using a density functional theory (DFT) approach. Local ensemble effects and longer range electronic effects in the alloys were considered, leading to a prediction for optimal hydrogenation activity by Pd57Au43NPs. PdAuNPs obtained from microwave-assisted syntheses were also found to be more highly active than analogous NPs prepared conventionally. Quantitative solution-state 1H NMR studies suggest that significantly less PVP was incorporated into PdAuNPs synthesized under microwave heating.Keywords: alloy nanoparticles; density functional theory (DFT); heterogeneous catalysis; hydrogenation; microwave synthesis; palladium−gold alloys

A 3-dimensional networked molecular cage, NMC-1, has been synthesized. This macrocycle-based framework was prepared from a solvothermal reaction involving a flexible organic building block, calix[4]pyrrole dibenzoic acid (H2L), and Pr(NO3)3·6H2O. A unique feature of NMC-1 is that it retains free calix[4]pyrrole molecules in the framework pores. Treatment with a fluoride anion source serves to destroy the network and allows release of the organic guest. The net result is a ‘molecular ship’ in a ‘breakable bottle’.

A combined inelastic neutron scattering (INS) and theoretical study of H2 sorption was performed in PCM-16, a phosphine coordination material (PCM) with the empirical formula [(CH3)2NH2][Dy2(tctpo)2(O2CH)] (tctpo = tris(p-carboxylato)triphenylphosphine oxide). INS measurements at different loadings of H2 revealed a peak occurring at low rotational tunnelling energies (ca. 5–8 meV), which corresponds to a high barrier to rotation and, therefore, a strong interaction with the host. Molecular simulations of H2 sorption in PCM-16 revealed that the H2 molecules sorbed at two main sites in the material: (1) the (CH3)2NH2+ counterions and (2) within the small pores of the framework. Two-dimensional quantum rotation calculations revealed that the peak occurring from approximately 5–8 meV in the INS spectra for PCM-16 is associated with sorption onto the (CH3)2NH2+ ions. These counterions provide for the strongest H2 sorption sites in the material, which corresponds to an isosteric heat of adsorption (Qst) value of close to 8 kJ mol–1. The calculated rotational barrier for the (CH3)2NH2+–H2 interaction in PCM-16 (45.60 meV) is higher than those for a number of extant metal–organic frameworks (MOFs), especially those that contain open-metal sites. This study provides insights into the H2 sorption mechanism in a PCM for the first time and shows how the inclusion of counterions in porous materials is a promising method to increase the H2 sorption energetics in such materials.

High surface area (367 m2 g−1) meso-porous Co3O4 was investigated as the precursor of the anode material for lithium and also sodium ion batteries. Co3O4 is considered a potential anode material due to its theoretical capacity of 890 mA h g−1, over twice that of graphite. This comparatively higher capacity can be safely charged at rapid rates owing to a relatively high Li-insertion potentials, but, consequently, the discharged energy is yielded at an average potential near 2 V vs. Li/Li+, with full Li-extraction achieved over a continuum of potentials up to 3 V. The products of the lithium reduction of Co3O4 cycle stably from 0.01–3.0 V vs. Li/Li+ with 600–900 mA h g−1 capacity retention at C rates from 1–5; the products of its sodium reduction cycle stably from 0.01–3.0 V vs. Na/Na+ at C-rates up to 1 C with a lower 150–400 mA h g−1 capacity retention owing to greater ionic impedance. TEM, SAED and XRD were used to examine the cycled material and the stable performance is attributed to finding that the mesoporous structure is retained. Evaluation of five electrolyte formulations testing EC, FEC and Cl-EC showed that the stable meso-porous structure was best cycled with 5% FEC in EC:DEC at high charge/discharge rates, retaining 77% of its initial capacity at 5 C in a rate test. Comparison of the AC impedance spectra and of the XPS of the SEIs formed in the presence and in the absence of 5 vol% FEC shows that the SEI formed in the presence of FEC contains lithium fluoride and its carbonate layer is thinner than that formed in its absence, resulting in lesser impedance to Li migration through the SEI and facile ion de-solvation, improving the cycling performance. In cycling stability tests with EC:DEC, irregular cycling behaviour attributable to abrupt rises in cell resistance was regularly observed after testing over a few hundred cycles. Long-term cycling irregularities are inhibited by halogenated solvents and completely eliminated by adding fluoroethylene carbonate (FEC).

The synthesis and catalytic properties of two new 1,2-acenaphthenyl N-heterocyclic carbene-supported palladium(II) catalysts are presented. The acenaphthenyl carbene has been prepared with mesityl or 1,5-diisopropyl N-aryl substituents. Comprehensive catalytic studies for the Suzuki coupling of aryl halides with aryl boronic acids have been conducted. In general, the diisopropyl-functionalised catalyst showed superior selectivity and reactivity. A comparison of the catalytic performances in dichloromethane, toluene and water at low temperatures (30–40 °C) is also presented. Both catalysts were proficient in the homogeneous Suzuki coupling of aryl iodides, bromides and chlorides with boronic acids in dichloromethane. Similar reactions in water led to the formation of insoluble colloidal catalytic species that still exhibited high activity in the Suzuki reaction with aryl chlorides. Reactions performed in toluene showed intermediate results; partial catalyst decomposition led to concomitant homogeneous and heterogeneous catalysis. The heterogeneous palladium precipitates could be easily recovered by filtration and reactivated for subsequent use. Activation energies determined for aryl bromide-based Suzuki reactions were found to be in the range of 159–171 kJ mol−1 in organic solvents and 111–116 kJ mol−1 in water. The corresponding activation energy for the aryl chloride was found to be 322 kJ mol−1 in water.

The porous Phosphine Coordination Material, PCM-10 contains abundant free P(III) donor sites that can be subjected to a variety of post-synthetic modifications. The diverse P(III)/P(V) organic reactivity and coordination chemistry available to aryl phosphines have been exploited to decorate the pores of PCM-10, allowing for an extensive structure–function study. Polar P═O moieties, charged P+–CH3 phosphonium species with exchangeable coanions (I–, F–, BF4–, and PF6–) and P–AuCl groups have been successfully post-synthetically incorporated. These modifications directly affect the strength of the resulting host–guest interactions, as demonstrated by comparative sorption studies of CO2, H2, and other gases in the solid-state. Broad tunability of the enthalpy of CO2 adsorption is observed: incorporation of BF4– ions inside the pores of PCM-10 results in 24% enhancement of the isosteric adsorption enthalpy of CO2 compared to the parent material, while F– anions induce a 36% reduction. Meanwhile, AuCl-decorated PCM-10 shows a high H2 sorption capacity of 4.72 wt % at 77 K and 1.0 bar, versus only 0.63 wt % in the unmodified material.

Two new isostructural phosphine coordination materials, Ln-PCM-21 (Ln = Pr, Nd), have been obtained using a tris(p-carboxylated) methyltriphenylphosphonium ligand that is formally dianionic when triply deprotonated, allowing access to materials based on uncommon metal-to-ligand ratios. The polymers of the formula [Ln3(mptbc)4]X·solv (X = Cl–, NO3–) are cationic and contain unusual, linear oxo-bridged [Ln3]9+ clusters. Magnetic susceptibility data for both the Pr and Nd analogues has been compared to models based on three contrasting approaches.

•We synthesize Rh nanoparticles in ionic liquid media using both conventional and microwave heating.•Ionic liquid coordination to the Rh nanoparticle surface was confirmed by FT-IR spectroscopy and XPS.•The Rh nanoparticles were active for the vapor-phase hydrogenation of cyclohexene.A comparative study of the synthesis of Rh nanoparticles (RhNPs) in ionic liquid media (1-butyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide) by conventional and microwave heating is presented. Controlled injection of hydrated RhCl3 precursor into mixtures of the ionic liquid and poly(N-vinylpyrrolidone) under convective electrical heating yielded near-monodisperse (6.9 ± 1.1 nm) RhNPs with a mixture of morphologies. In contrast, identical reactions performed under microwave-assisted heating showed greater morphological selectivity, resulting in largely homogeneous samples of cubic and truncated cubic RhNPs (5.7 ± 0.9 nm). Interestingly, X-ray photoelectron spectroscopic analysis of the microwave-synthesized RhNPs revealed a greater surface population of BMIM-NTf2 when compared to the conventionally prepared RhNPs. This is indicative of a larger degree of incorporation of ionic liquid monomers coordinated to the RhNP surfaces and may be responsible for the enhanced shape selectivity. The catalytic ability of the as-synthesized nanoparticles was probed through vapor-phase cyclohexene hydrogenation reactions, yielding average TOF values of 9.2 for supported RhNPs.Rhodium nanoparticles have been prepared using an ionic liquid and organic polymer as co-capping agents; the effects of microwave-assisted heating are compared to conventional heating, and the resulting products are compared as heterogeneous hydrogenation catalysts under model conditions.

Noble metal alloys are important in large-scale catalytic processes. Alloying facilitates fine-tuning of catalytic properties via synergistic interactions between metals. It also allows for dilution of scarce and expensive metals using comparatively earth-abundant metals. RhAg and RhAu are classically considered to be immiscible metals. We show here that stable RhM (M = Ag, Au) nanoparticles with randomly alloyed structures and broadly tunable Rh:M ratios can be prepared using a microwave-assisted method. The alloyed nanostructures with optimized Rh:M compositions are significantly more active as hydrogenation catalysts than Rh itself: Rh is more dilute and more reactive when alloyed with Ag or Au, even though the latter are both catalytically inactive for hydrogenation. Theoretical modeling predicts that the observed catalytic enhancement is due to few-atom surface ensemble effects in which the overall reaction energy profile for alkene hydrogenation is optimized due to Rh–M d-band intermixing.Keywords: alloy nanoparticles; density functional theory (DFT); heterogeneous catalysis; hydrogenation; immiscible alloys; microwave synthesis;

MCl2 complexes of a new p-carboxylated 1,2-bis(diphenylphosphino)benzene ligand are effectively utilized as tetratopic building blocks to prepare isostructural porous coordination polymers with accessible reactive metal sites (M = Pd, Pt). The crystalline materials exhibit unusual and fully reversible H2 sorption at 150 °C. Post-synthetic reactivity is also possible, in which Pt–Cl bonds can be activated to provide organometallic species in the pores.

PCM-15 is a robust and recyclable sensor for the effective discrimination of a wide range of small molecules. Sensing is achieved by direct attenuation of the luminescence intensity of Tb(III) ions within the material. A competition study involving trace amounts of NH3 in H2 gas shows that PCM-15 can be used to quantitatively detect trace analytes.

A microwave-assisted heating method allows for the convenient and reproducible synthesis of defined Au–Rh core–shell metallic nanoparticles with tuneable shell thicknesses. Nanoparticles with shells as thin as two Rh monolayers can be prepared, which are effective in vapour-phase hydrogenation catalysis at room temperature without the need for pre-treatment. Particles with Rh shells consisting of two or four Rh overlayers show similar catalytic properties and are both significantly more highly active than pure Rh nanoparticles, per mol of Rh employed.

Mesoporous Co3O4 with hexagonally ordered cylindrical channels has been synthesized by a single-step method using Pluronic soft micellar templates. The resulting material has been directly compared to isomorphous Co3O4 that was obtained via an established but laborious five-step nanocasting method. The soft template route employs only surfactant templates and a decane additive, which yields directly mesoporous Co3O4 by a gelling process in a carefully controlled basic (pH = 12.7) alcohol solution at 35 °C. The method is significantly faster and more economical than conventional nanocasting, and has similar overall reproducibility to the conventional multi-step route. The soft templated Co3O4 displays long-range ordered cylindrical microchannels with crystalline walls. Most importantly, it exhibits an unparalleled N2 BET surface area of 367 m2 g−1.

PCM-16 is a phosphine coordination material comprised of Dy(III) and triphenylphosphine oxide, which displays the highest reported CO2 BET surface area for a Ln(III) coordination polymer of 1511 m2 g–1. PCM-16 also adsorbs 2.7 wt % H2 and 65.1 wt % O2 at 77 K and 0.97 bar. The adsorption–desorption behavior of a series of organic vapors has been studied in PCM-16 to probe the nature of certain host–guest interactions in the pores. Aromatic and polar guest species showed high uptakes and marked adsorption/desorption hysteresis, while aliphatic vapors were less easily adsorbed. The surface area of PCM-16 could be increased significantly (to 1814 m2 g–1) via exchange of Me2NH2+ cations in the pores with smaller NH4+ groups.

The structure, stability, gas sorption properties and luminescence behaviour of a new lanthanide-phosphine oxide coordination material are reported. The polymer PCM-15 is based on Tb(III) and tris(p-carboxylated) triphenylphosphine oxide and has a 5,5-connected net topology. It exhibits an infinite three-dimensional structure that incorporates an open, two-dimensional pore structure. The material is thermally robust and remains crystalline under high vacuum at 150 °C. When desolvated, the solid has a CO2 BET surface area of 1187 m2 g−1 and shows the highest reported uptake of both O2 and H2 at 77 K and 1 bar for a lanthanide-based coordination polymer. Isolated Tb(III) centres in the as-synthesized polymer exhibit moderate photoluminescence. However, upon removal of coordinated OH2 ligands, the luminescence intensity was found to approximately double; this process was reversible. Thus, the Tb(III) centre was used as a probe to detect directly the desolvation and resolvation of the polymer.

PCM-14 is a dense coordination polymer formed from Ca(II) and an unusual organophosphonium ligand. The dehydrated framework contains 3-coordinate Ca(II) sites within catenated, chiral 3,3-connected nets. PCM-14 exhibits a stark CO2 sorption selectivity over H2, N2 and O2. The maximum CO2 uptake was shown to be highly sensitive to the material pretreatment evacuation temperature.

An extensive comparative study of the effects of microwave versus conventional heating on the nucleation and growth of near-monodisperse Rh, Pd, and Pt nanoparticles has revealed distinct and preferential effects of the microwave heating method. A one-pot synthetic method has been investigated, which combines nucleation and growth in a single reaction via precise control over the precursor addition rate. Using this method, microwave-assisted heating enables the convenient preparation of polymer-capped nanoparticles with improved monodispersity, morphological control, and higher crystallinity, compared with samples heated conventionally under otherwise identical conditions. Extensive studies of Rh nanoparticle formation reveal fundamental differences during the nucleation phase that is directly dependent on the heating method; microwave irradiation was found to provide more uniform seeds for the subsequent growth of larger nanostructures of desired size and surface structure. Nanoparticle growth kinetics are also markedly different under microwave heating. While conventional heating generally yields particles with mixed morphologies, microwave synthesis consistently provides a majority of tetrahedral particles at intermediate sizes (5–7 nm) or larger cubes (8+ nm) upon further growth. High-resolution transmission electron microscopy indicates that Rh seeds and larger nanoparticles obtained from microwave-assisted synthesis are more highly crystalline and faceted versus their conventionally prepared counterparts. Microwave-prepared Rh nanoparticles also show approximately twice the catalytic activity of similar-sized conventionally prepared particles, as demonstrated in the vapor-phase hydrogenation of cyclohexene. Ligand exchange reactions to replace polymer capping agents with molecular stabilizing agents are also easily facilitated under microwave heating, due to the excitation of polar organic moieties; the ligand exchange proceeds with excellent retention of nanoparticle size and structure.Keywords: ligand exchange; microwave synthesis; palladium nanoparticles; platinum nanoparticles; polyol method; rhodium nanoparticles; seeding and growth; shape control

The new porous phosphine coordination material, PCM-11, is an unusual 8,4-connected coordination polymer with an open 3-D pore structure, formed by reaction of Mg(II) with tris(para-carboxylato)triphenylphosphine oxide. The highly ionic nature of the metal–ligand bonding results in excellent thermal stability upon desolvation (>460 °C). PCM-11 is easily activated for small molecule sorption at low temperature without the requirement for solvent pre-exchange. It adsorbs 47.5 wt% CO2 at 11.6 bar and 30 °C.

The hexaanion of mellitic acid, mel = (C6(CO2)6)6−, links metal ions into extensively connected magnetic coordination polymers. Reaction of alkali metal mellitate salts, M6(mel) (M = K, Rb), with M′Cl2 precursors (M′ = Mn, Co, Ni) under mild (473 K) hydrothermal conditions yields an extensive family of isostructural 3-dimensional mixed alkali metal/transition metal polymers of general formula M2[M′2(mel)(OH2)2] (M/M′ = K/Mn (1a); K/Co (1b); K/Ni (1c); Rb/Mn (2a); Rb/Co (2b); Rb/Ni (2c)). These materials incorporate distorted 2-dimensional magnetic hexagonal nets with a honeycomb topology that are exclusively based on metal-carboxylate-metal bridging interactions. A further isostructural alkali metal-free Co2+ material with NH4+ cations, (NH4)2[Co2(mel)(OH2)2] (3), produced by reaction of H6mel with [Co(NH3)6]Cl3 is also presented. The magnetic susceptibility data for 1a−c, 2a−c, and 3 are presented. The susceptibility data for the Mn(II)- and Ni(II)-containing phases have been analyzed using a simple Mean Field Theory approach, and have been modeled using a high temperature series expansion. The comparative magnetism of the Co(II) phases is also presented, and is more complicated because of significant spin−orbit coupling effects.

The synthesis and catalytic properties of two new 1,2-acenaphthenyl N-heterocyclic carbene-supported palladium(II) catalysts are presented. The acenaphthenyl carbene has been prepared with mesityl or 1,5-diisopropyl N-aryl substituents. Comprehensive catalytic studies for the Suzuki coupling of aryl halides with aryl boronic acids have been conducted. In general, the diisopropyl-functionalised catalyst showed superior selectivity and reactivity. A comparison of the catalytic performances in dichloromethane, toluene and water at low temperatures (30–40 °C) is also presented. Both catalysts were proficient in the homogeneous Suzuki coupling of aryl iodides, bromides and chlorides with boronic acids in dichloromethane. Similar reactions in water led to the formation of insoluble colloidal catalytic species that still exhibited high activity in the Suzuki reaction with aryl chlorides. Reactions performed in toluene showed intermediate results; partial catalyst decomposition led to concomitant homogeneous and heterogeneous catalysis. The heterogeneous palladium precipitates could be easily recovered by filtration and reactivated for subsequent use. Activation energies determined for aryl bromide-based Suzuki reactions were found to be in the range of 159–171 kJ mol−1 in organic solvents and 111–116 kJ mol−1 in water. The corresponding activation energy for the aryl chloride was found to be 322 kJ mol−1 in water.

A microwave-assisted heating method allows for the convenient and reproducible synthesis of defined Au–Rh core–shell metallic nanoparticles with tuneable shell thicknesses. Nanoparticles with shells as thin as two Rh monolayers can be prepared, which are effective in vapour-phase hydrogenation catalysis at room temperature without the need for pre-treatment. Particles with Rh shells consisting of two or four Rh overlayers show similar catalytic properties and are both significantly more highly active than pure Rh nanoparticles, per mol of Rh employed.

Mesoporous LaMnO3 with bulk surface areas in the range 225–300 m2 g−1 were prepared by direct overgrowth around the short-channel version of SBA-15 silica. The extent of LaMnO3 growth was found to be affected by the polarity of solvent system used to impregnate the SBA-15 with La3+ and Mn2+ precursors. The resulting LaMnO3–SiO2 composites were stable in refluxing NaOH, suggesting that the SiO2 was fully encapsulated. The composites were structurally characterized using a range of techniques including 2-D elemental mapping and Raman spectroscopy. The electrochemical behavior of the composites was tested for pseudocapacitance, which revealed normalized specific capacitances over 200 F g−1.

Mesoporous Co3O4 with hexagonally ordered cylindrical channels has been synthesized by a single-step method using Pluronic soft micellar templates. The resulting material has been directly compared to isomorphous Co3O4 that was obtained via an established but laborious five-step nanocasting method. The soft template route employs only surfactant templates and a decane additive, which yields directly mesoporous Co3O4 by a gelling process in a carefully controlled basic (pH = 12.7) alcohol solution at 35 °C. The method is significantly faster and more economical than conventional nanocasting, and has similar overall reproducibility to the conventional multi-step route. The soft templated Co3O4 displays long-range ordered cylindrical microchannels with crystalline walls. Most importantly, it exhibits an unparalleled N2 BET surface area of 367 m2 g−1.

High surface area (367 m2 g−1) meso-porous Co3O4 was investigated as the precursor of the anode material for lithium and also sodium ion batteries. Co3O4 is considered a potential anode material due to its theoretical capacity of 890 mA h g−1, over twice that of graphite. This comparatively higher capacity can be safely charged at rapid rates owing to a relatively high Li-insertion potentials, but, consequently, the discharged energy is yielded at an average potential near 2 V vs. Li/Li+, with full Li-extraction achieved over a continuum of potentials up to 3 V. The products of the lithium reduction of Co3O4 cycle stably from 0.01–3.0 V vs. Li/Li+ with 600–900 mA h g−1 capacity retention at C rates from 1–5; the products of its sodium reduction cycle stably from 0.01–3.0 V vs. Na/Na+ at C-rates up to 1 C with a lower 150–400 mA h g−1 capacity retention owing to greater ionic impedance. TEM, SAED and XRD were used to examine the cycled material and the stable performance is attributed to finding that the mesoporous structure is retained. Evaluation of five electrolyte formulations testing EC, FEC and Cl-EC showed that the stable meso-porous structure was best cycled with 5% FEC in EC:DEC at high charge/discharge rates, retaining 77% of its initial capacity at 5 C in a rate test. Comparison of the AC impedance spectra and of the XPS of the SEIs formed in the presence and in the absence of 5 vol% FEC shows that the SEI formed in the presence of FEC contains lithium fluoride and its carbonate layer is thinner than that formed in its absence, resulting in lesser impedance to Li migration through the SEI and facile ion de-solvation, improving the cycling performance. In cycling stability tests with EC:DEC, irregular cycling behaviour attributable to abrupt rises in cell resistance was regularly observed after testing over a few hundred cycles. Long-term cycling irregularities are inhibited by halogenated solvents and completely eliminated by adding fluoroethylene carbonate (FEC).

The structure, stability, gas sorption properties and luminescence behaviour of a new lanthanide-phosphine oxide coordination material are reported. The polymer PCM-15 is based on Tb(III) and tris(p-carboxylated) triphenylphosphine oxide and has a 5,5-connected net topology. It exhibits an infinite three-dimensional structure that incorporates an open, two-dimensional pore structure. The material is thermally robust and remains crystalline under high vacuum at 150 °C. When desolvated, the solid has a CO2 BET surface area of 1187 m2 g−1 and shows the highest reported uptake of both O2 and H2 at 77 K and 1 bar for a lanthanide-based coordination polymer. Isolated Tb(III) centres in the as-synthesized polymer exhibit moderate photoluminescence. However, upon removal of coordinated OH2 ligands, the luminescence intensity was found to approximately double; this process was reversible. Thus, the Tb(III) centre was used as a probe to detect directly the desolvation and resolvation of the polymer.

PCM-14 is a dense coordination polymer formed from Ca(II) and an unusual organophosphonium ligand. The dehydrated framework contains 3-coordinate Ca(II) sites within catenated, chiral 3,3-connected nets. PCM-14 exhibits a stark CO2 sorption selectivity over H2, N2 and O2. The maximum CO2 uptake was shown to be highly sensitive to the material pretreatment evacuation temperature.

The new porous phosphine coordination material, PCM-11, is an unusual 8,4-connected coordination polymer with an open 3-D pore structure, formed by reaction of Mg(II) with tris(para-carboxylato)triphenylphosphine oxide. The highly ionic nature of the metal–ligand bonding results in excellent thermal stability upon desolvation (>460 °C). PCM-11 is easily activated for small molecule sorption at low temperature without the requirement for solvent pre-exchange. It adsorbs 47.5 wt% CO2 at 11.6 bar and 30 °C.

PCM-15 is a robust and recyclable sensor for the effective discrimination of a wide range of small molecules. Sensing is achieved by direct attenuation of the luminescence intensity of Tb(III) ions within the material. A competition study involving trace amounts of NH3 in H2 gas shows that PCM-15 can be used to quantitatively detect trace analytes.

A 3-dimensional networked molecular cage, NMC-1, has been synthesized. This macrocycle-based framework was prepared from a solvothermal reaction involving a flexible organic building block, calix[4]pyrrole dibenzoic acid (H2L), and Pr(NO3)3·6H2O. A unique feature of NMC-1 is that it retains free calix[4]pyrrole molecules in the framework pores. Treatment with a fluoride anion source serves to destroy the network and allows release of the organic guest. The net result is a ‘molecular ship’ in a ‘breakable bottle’.