Ultrathin porous Ni(OH)2 sheets were grown on the surface of nano-chain CoB as cores via a facile two-step solution-based method at ambient conditions. The resultant CoB@Ni(OH)2 of 27.89 wt% Ni(OH)2 loading has a high specific capacitance of 1504.4 F g−1 at 0.5 A g−1, 1293.7 F g−1 at 2 A g−1 and 746.8 F g−1 at 6 A g−1.

It has been recently reported that engineering the pores within alloy nanoparticles leads to improvement in the electrochemical activity of nanoparticle catalysts due to the enhanced electrochemical active surface areas. However, to date, few works have reported the tailoring intraporosity within alloy nanoparticle networks. In this study, a different and innovative approach was adopted to yield a network-like PtCo catalyst composed of intraporous nanoparticles used a cotton-like PtCo precursor material. It was found that the network-like structure and intrapores within the nanoparticles could co-evolve after careful controlled electrochemical dealloying, whereby Pt-rich surface was formed during the leaching out of Co in the first 13th potentiostatic cyclic voltammetry cycles from +0.056 to +1.256 V vs. RHE. Electrochemical data also showed that the mass and area activity of the obtained PtCo networks toward methanol oxidation reaction (MOR) was nearly 3.9, 2.0 and 2.1 times higher than that of commercial Pt/C, PtRu/C catalyst respectively, and much higher than that of Pt3Co networks made of only solid nanoparticles. Moreover, it was observed that such networks exhibited high CO oxidation ability whilst maintaining high catalytic durability under an applied potential of +0.756 V vs. RHE. It was found that developing network-like catalysts composed of porous nanoparticles can be an efficient strategy to improve the catalytic activity and durability of fuel cell catalysts.

This study presents the preparation of novel cage-like MnO2-Mn2O3 particles that have high surface area and macro-porosity. Carbonaceous (C) spheres were first prepared hydrothermally as templates for a subsequent hydrothermal step of MnO2 shell precipitation. Adjusting the Mn precursor concentration and hydrothermal dwell time resulted in MnO2 shells of different thickness. Following calcination to remove carbon, thinner shells resulted in cage-like structure and a higher degree of Mn2O3 content, while thicker shells produced complete hollow spheres. The cage-like MnO2-Mn2O3 hollow spheres (CMHS) produced a 30% larger specific capacity than that of complete hollow spheres at 0.05 A g−1. On a 100 fold current density increase to 5 A g−1 CMHS had a 49.9% of its initial specific capacitance, and had 77.4% capacitance retention after 2000 cycles at 2 A g−1. Cage-like particles, through their high surface area and macro-porosity, thus afford a promising target structure for supercapacitor materials, and can be prepared as described herein.

NixCoy alloy pompoms formed by the aggregation of nano ultrathin sheets were prepared by simultaneous reduction of NiCl2 and CoCl2 with NaBH4via a liquid–liquid interface reaction. Ni1Co3 pompoms produced markedly higher activity and stability as hydrazine oxidation catalysts than Ni, Co and other NixCoy pompom catalysts.

A N-doped porous carbon material was prepared by pyrolysis of fish bones, a natural material and sustainable source. The morphology and structure of the N-doped porous carbon were investigated by scanning electron microscopy, X-ray diffraction, Raman spectroscopy and N2 isotherms. The mass content of N in the obtained sample measured by X-ray photoelectron spectroscopy is about 6.02%. Electrochemical characterization reveals that the obtained N-doped porous carbon possesses excellent catalytic activity towards oxygen reduction reaction in alkaline medium, as well as long-term stability in catalysis.

The design of alloy networks is an important fundamental and applied research challenge in the area of catalysis due to the high surface area, gas permeability and electrical conductivity of alloy network structures. Herein amorphous PtNiP particle networks were prepared via the NaBH4 co-reduction process. Moreover, the reaction temperature control from 0 °C to 80 °C was shown to be a powerful tool for the ‘tuning’ of particle sizes. Electron microscopy, X-ray diffraction and selected area electron diffraction were used to show the morphology, the amorphous behavior and the changes in particle size of the particle networks. The results of the electrochemical performance showed that the amorphous PtNiP particle networks had better catalytic activity towards hydrazine oxidation compared to the Pt and PtNi networks. The electrocatalytic activity reached a peak value, 0.62 mA at −0.63 V, at a PtNiP-50 electrode. The correlation between the particle size of the amorphous PtNiP particle networks and their electrocatalytic activity for the hydrazine oxidation reaction provided the opportunity to develop highly active electrocatalysts for hydrazine fuel cells.

PdNiP alloy nanoparticle networks (PdNiP NN) were prepared by simultaneous reduction of PdCl2, NiCl2 and NaH2PO2 with NaBH4via a gas–liquid interface reaction at room temperature using N2 bubbles. PdNiP NN had markedly higher activity and durability for ethanol oxidation than PdNi nanoparticle networks and PdNiP grain aggregates.

•Porous carbon nanotubes with a diameter of ca. 300–400 nm (LPCNs) derived from lysine.•LPCNs exhibit higher activity than Pt/C (20 wt%) for oxygen reduction reaction (ORR).•LPCNs show higher stability for ORR and tolerance for methanol than Pt/C (20 wt%).•The superior performance of LPCNs results from the unique structure and the doped effect.N-doped carbon nanotubes are highly favored for use as electrocatalysts for oxygen reduction reaction (ORR) because of their relatively low cost and superior catalytic activity. Here, Lysine-derived porous carbon nanotubes (LPCNs) with large inner cavities of ca. 300–400 nm are reported as electrocatalyst for ORR. LPCNs exhibit 28.3 mV of more positive half-wave-potential than that of commercial Pt/C. In addition, LPCNs is much more stable and tolerant to fuel crossover effect than Pt/C. The above superiorities make it a promising candidate for substituting noble metal catalysts as a cathode catalyst for ORR.

•Nitrogen-rich mesoporous carbon derived from melamine (MNMC) is prepared.•MNMC shows good catalytic activity for oxygen reduction reaction.•The good performance is derived the special structure.Melamine-derived N-doped mesoporous carbon (MNMC) is synthesized by the pyrolysis of lysine and melamineunder at nitrogen atmosphere using ferric chloride as a dopant and SiO2 nanoparticles as hard templates to form mesoporous architecture. The N content in the bulk of carbon materials is as high as 11.3% and ca. 40.6% of N is in the form of pyridinic-N. The surface area of MNMC is ca. 650 m2 g−1 with a pore size distribution in the range of 2.2–34.5 nm. Compared to commercial Pt/C (20 wt%), MNMC exhibits much better electrocatalytic activity, better durability, and higher methanol tolerance for oxygen reduction reaction (ORR) in alkaline medium. Particularly, the onset ORR potential and half-wave ORR potential of MNMC are 1.059 and 0.871 V vs. RHE respectively, which are higher than those of commercial Pt/C.Melamine-derived mesoporous nitrogen-rich carbon showed a high electrocatalytic activity in oxygen reduction reaction in alkaline media.

•Amorphous PtRuNiP/C catalyst with different disorder degree was prepared.•Amorphous PtRuNiP-300/C catalyst showed high activity for methanol oxidation.•The correlation between amorphous structure and their activity was established.Amorphous metallic nanoparticles hold much promise for use as electrocatalysts, as their surface is rich in low-coordination sites and defects which could act as the electrocatalyt's active sites. In this study, we describe new findings on amorphous platinum–ruthenium–nickel–phosphorous nanoparticles supported on carbon (PtRuNiPa/C) and the comparison between their catalytic activity and the degree of disorder. The nanoscale amorphous structure with different degrees of disorder are probed as a function of surface composition, particle size, and thermal treatment conditions using X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, selected area electron diffraction and electrochemical characterization. The results provide experimental evidence in support of nanoscale long-range disorder, medium-range disorder, and medium-range order evolution dependence on the catalyst synthesis temperature. More importantly, the results of the electrochemical performance investigation show that the amorphous structures with medium-range disorder have not only better catalytic activity, but also better durability for methanol oxidation compared to the long-range disorder and medium-range order structure. These results provide an opportunity for establishing the correlation between the nanoscale amorphous structure and their electrocatalytic activity for methanol oxidation reaction, which could play an important role in developing new high active catalysts for direct methanol fuel cells.PtRuNiP/C catalysts with different disorder degree were prepared, and the amorphous PtRuNiP/C catalyst with appropriate disorder degree exhibits the best performance for methanol oxidation than the other catalysts due to the surface composition and the electronic effect from disorder structure.

•Ultrafine amorphous PtNiP nanoparticles on carbon (PtNiPa/C) were prepared.•PtNiPa/C showed higher catalytic activity for oxygen reduction reaction (ORR) than PtNi/C.•The high activity of PtNiPa/C derived from the small particle size and electron effect.Design of amorphous noble metallic nanoparticle electrocatalysts is an important fundamental and applied research challenge. Here, we describe new findings of a detailed investigation of the amorphous platinum–nickel–phosphorus nanoparticles supported on carbon (PtNiPa/C), which were characterized using X-ray diffraction, transmission electron microscopy, selected area electron diffraction. Compared to the crystal platinum–nickel–phosphorus nanoparticles supported on carbon (PtNiPc/C) and PtNi/C, PtNiPa/C catalyst has more positive half-wave potential and higher mass activity for oxygen reduction reaction (ORR). In addition, the ORR on PtNiPa/C electrode follows the 4 electron reaction pathway.Ultrafine amorphous PtNiP nanoparticles supported on carbon showed a higher activity than PtNi and crystalline PtNiP nanoparticles supported on carban for oxygen reduction reaction, which is attributed to the small particle size and electron effect.

•A mesoporous support derived soybean, e.g. CS, was prepared.•Pt nano sized dendrites were dispersed on the surface of CS.•Pt/CS has high catalytic activity for CO and methanol oxidation.In this work, a low cost and nitrogen-containing carbon (CS) with mesoporous structure and high surface area is synthesized by carbonizing soybean. It is found that the prepared CS has excellent textural properties such as high specific surface areas and large pore diameters. TEM images show that the Pt nano-sized dendrites are well formed on the surface of CS. Compared to Pt supported on Vulcan carbon XC-72, electrochemical results show that Pt supported on CS possesses a higher electrocatalytic activity and better durability in methanol oxidation reaction, which are mainly attributed to the support effect of CS resulting in the unique morphology of Pt particles and high content of Pt(0). These results indicate that CS has great potential as a high-performance catalyst support for fuel cell electrocatalysis.Pt nano sized dendrites supported on soybean-derived-carbon (CS) have shown a higher activity than Pt/XC-72 for CO and methanol oxidation, which is attributed to the synergy effect between mesoporous CS support and Pt nano sized dendrites.

•Mn-N dual doped carbon, e.g. Mn-CNx, was prepared.•Mn-CNx showed good catalytic activity for oxygen reduction reaction.•Synergy among Mn, N and C results in the enhanced activity of Mn-CNx.A highly active electrocatalyst for oxygen reduction reaction, manganese modified glycine derivative-carbon (Mn-CNx), is synthesized by a two-step carbonizing process. X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy are used to characterize structure and morphology of the catalysts. Electrochemical tests show that Mn-CNx has higher catalytic activity for oxygen reduction reaction than CNx derived glycine and Mn modified Vulcan carbon. Moreover, the half-wave potential of Mn-CNx is only 12 mV lower than that of commercial Pt/C. Mn-CNx also has excellent durability to methanol crossover in alkaline solution, and thus provides a promising low cost, non-precious metal cathode catalyst for fuel cells.

•Heterostructure catalyst, isolated-Fe3O4 nanoparticles and CNx layers derived from lysine, was prepared.•Fe3O4-CNx-Lys exhibits comparable catalytic activity to commercial Pt/C for oxygen reduction reaction.•The enhanced activity of Fe3O4-CNx-Lys is synergic effect of Fe3O4 and CNx.In order to seek heterogeneous electrocatalyst with efficient catalytic activity for oxygen reduction reaction (ORR), Fe3O4-CNx composite reported in our previous work was studied as electrocatalyst for ORR and showed poor catalytic activity. To improve the catalytic activity, Fe3O4-CNx composite is modified by the CNx layers derived from lysine through pyrolysis. The physical characterization show that the coral-shaped morphology of the resultant composite (Fe3O4-CNx-Lys) is still retained, while the degree of its graphitic crystalline increases. Besides, Fe3O4-CNx-Lys has 364.7 m2 g−1 of surface area with hierarchical porous structure. Electrochemical tests show that the catalytic activity Fe3O4-CNx-Lys for ORR is not only higher than those Fe3O4-CNx, XC-72-Lys derived from lysine and XC-72 Vulcan carbon but also comparable to that of commercial Pt/C (20 wt%).

In this study we report that ultrafine amorphous metallic nanoparticles have a surface structure that is rich in both low-coordination sites and defects that coincides with increased methanol oxidation activity. Ultrafine amorphous platinum-phosphorous nanoparticles supported on Vulcan carbon (PtPa/C) were synthesized, followed by increasing degrees of heat treatment to obtain higher levels of crystallinity in the supported PtP particles. Structural and compositional analysis by various techniques allowed correlation between the structures of various PtP states and their resultant catalytic methanol oxidation activity. Increasing heat treatment temperature increased both the crystallinity and average size of the supported PtP particles. Both factors coincided with decreased methanol oxidation activity and lower carbon monoxide tolerance. The most amorphous PtP nanoparticles had the highest catalytic methanol oxidation activity and strongest tolerance for carbon monoxide.

Using selenium functionalized carbon as supports, platinum–ruthenium nanoparticles were highly dispersed on the carbon surface, and showed improved electrochemical properties for methanol electrooxidation. The method provides a new route for functionalization of the carbon surface on which to disperse noble metal nanoparticles for application as electrocatalysts in fuel cells.Highlights► Vulcan carbon can be modified by selenium atoms. ► Se on the surface of carbon affects the dispersion of PtRu particles. ► PtRu/Se–C showed higher electrocatalytic activity toward methanol oxidation.

•Heterostructure core, e.g. PdSn–SnO2, was prepared.•Pt layers were deposited on PdSn–SnO2 nanoparticles supported on carbon.•The Pt@PdSn–SnO2/C catalyst has high catalytic activity for ethanol oxidation.To enhance the performance of heterostructure electrocatalysts for fuel cell and other applications, carbon-supported Pt decorating PdSn–SnO2 nanoparticles are prepared and characterized by X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscopy. The electrochemical results show higher ethanol oxidation activity of heterostructured catalysts than that of Pt@PdSn/C, PtSn/C and PdSn–SnO2/C catalysts. This result demonstrates significant potential for utilizing heterostructure-core synthesis in the preparation of novel core–shell catalysts.

Ni@Pd/C catalysts were synthesized, using Ni/C with different crystalline structures prepared with various ligands. A series of characterizations were performed by transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy. The results indicated the electrocatalysts with amorphous/crystalline (denoted as Nia and Nic) Ni structures decorated with Pd. The formic acid electrocatalytic oxidation results showed that the peak current of Nia@Pd/C was about 1.2 times higher than that of Nic@Pd/C. The good electrochemical performance and stability of Pd-modified amorphous Ni substrate reveals that the core structure plays an important role in the electrocatalytic activity and the change of the structure can improve the activity and stability of electrocatalysts.Graphical abstractThe better electrochemical performance of Niamorphous@Pd/C catalyst than Nicrystal@Pd/C catalyst results from the different crystal Ni core for formic acid oxidation reaction.Highlights► The Ni@Pt/C catalysts with different crystallization of Ni core were prepared. ► Niamorphous@Pd/C has higher activity than Nicrystal@Pd/C for formic acid oxidation. ► The structure of core affects the electrocatalytic activity of electrocatalysts.

•A composite support, e.g. CNx-MMT, was prepared.•Pt nanoparticles were deposited on CNx-MMT.•The Pt/CNx-MMT catalyst has high catalytic activity for methanol oxidation.A composite support based on nature clay, i.e. montmorillonite (MMT), shows great promise as support materials for Pt electrocatalyst for the methanol oxidation reaction in fuel cell anodes. The reported composite support (CNx-MMT) was prepared via carbonizing MMT which was covered by N-contented polymer. X-ray diffraction and transmission electron microscopy results showed that Pt nanoparticles can be well-dispersed on the composite support with highly dispersed tiny crystal Pt nanoparticles. Cyclic voltammetry measurements showed that the Pt/CNx-MMT has the enhanced electrocatalytic activity in methanol oxidation reaction. The developed Pt catalyst supported on new composite support is catalytically more active for methanol electrooxidation than Pt supported on the conventional carbon support and shows good stability, offering promising potential for application of MMT as support for fuel cell electrocatalysis.Pt nanoparticles supported on CNx-MMT have shown higher activity than Pt/C for methanol oxidation, which is attributed to the support effect.

Using hydrophilic nitrogen-doped carbon tubes (N-CTs) as supports, prepared by carbonization of the mixture of lysine and ferric chloride, ultrafine Pt nanoparticles were highly dispersed on the N-CT sidewalls. Electrochemical analyses found that the methanol oxidation activity of the Pt/N-CTs was ∼2.1 times that of a commercial Pt/C catalyst. The improved performance correlated to the high dispersion of ultrafine Pt nanoparticles and the synergistic effect between Pt and the N-CTs.

Ultrathin porous Ni(OH)2 sheets were grown on the surface of nano-chain CoB as cores via a facile two-step solution-based method at ambient conditions. The resultant CoB@Ni(OH)2 of 27.89 wt% Ni(OH)2 loading has a high specific capacitance of 1504.4 F g−1 at 0.5 A g−1, 1293.7 F g−1 at 2 A g−1 and 746.8 F g−1 at 6 A g−1.

PdNiP alloy nanoparticle networks (PdNiP NN) were prepared by simultaneous reduction of PdCl2, NiCl2 and NaH2PO2 with NaBH4via a gas–liquid interface reaction at room temperature using N2 bubbles. PdNiP NN had markedly higher activity and durability for ethanol oxidation than PdNi nanoparticle networks and PdNiP grain aggregates.

NixCoy alloy pompoms formed by the aggregation of nano ultrathin sheets were prepared by simultaneous reduction of NiCl2 and CoCl2 with NaBH4via a liquid–liquid interface reaction. Ni1Co3 pompoms produced markedly higher activity and stability as hydrazine oxidation catalysts than Ni, Co and other NixCoy pompom catalysts.