Oxide materials with redox capability have attracted worldwide attentions in many applications. Introducing defects into crystal lattice is an effective method to modify and optimize redox capability of oxides as well as their catalytic performance. However, the relationship between intrinsic characteristics of defects and properties of oxides has been rarely reported. Herein, we report a facile strategy to introduce defects by doping a small amount of Ni atoms (∼1.8 at. %) into ceria lattice at atomic level through the effect of microstructure of crystal on the redox property of ceria. Amazingly, a small amount of single Ni atom-doped ceria has formed a homogeneous solid solution with uniform lotuslike morphology. It performs an outstanding catalytic performance of a reduced T50 of CO oxidation at 230 °C, which is 135 °C lower than that of pure CeO2 (365 °C). This is largely attributed to defects such as lattice distortion, crystal defects and elastic strain induced by Ni dopants. The DFT calculation has revealed that the electron density distribution of oxygen ions near Ni dopant, the reduced formation energy of oxygen vacancy originated from local chemical effect caused by local distortion after Ni doping. These differences have a great effect on increasing the concentration of oxygen vacancies and enhancing the migration of lattice oxygen from bulk to a surface which is closely related to optimized redox properties. As a result, oxygen storage capacity and the associated catalytic reactivity has been largely increased. We have clearly demonstrated the change of crystal lattice and the charge distribution effectively modify its chemical and physical properties at the atomic scale.Keywords: atomic level doping; cerium oxide; CO oxidation; oxygen vacancy; solid solution;

A series of polyphosphazene nano-frameworks with electron-withdrawing capability have been produced and exhibited high activity as non-acidic heterogeneous catalysts for the dehydration of fructose to 5-hydroxymethylfurfural under mild conditions with good stability and recyclability. The unique cyclotriphosphazene unit and electron-withdrawing nature of the polymer backbone are essential for the catalytic performance.

Glycerolysis of triglycerides (corn oil) was carried out over CeO2 promoted CaO catalysts. CeO2 was introduced into CaO via the sol–gel combustion method with citrate as the precipitator. A strong interaction between CaO and CeO2 was revealed by XRD, XPS and Raman results, which results in an increased basic strength and amounts of strong basic sites. Moreover, the lixiviation of CaO in the glycerol at high temperature, which is the key problem in the glycerolysis reaction over CaO-based catalysts, was inhibited significantly. XRD, N2 adsorption–desorption isotherms and SEM results exhibit introducing CeO2 increases the surface area, pore volume and pore size of CaO catalysts, which are beneficial to the catalytic activity. The 2CaO–1CeO2 catalyst with strong basicity and large surface area achieved over 90 % conversion after 1 h while the lixiviated Ca decreased dramatically.

Selective dehydration of glycerol to value-added acrolein is an interesting catalytic process not only owing to the increasing coproduction of glycerol in the biodiesel production but also due to the emerging perspectives to provide a sustainable route for acrolein production. The use of zeolites in glycerol dehydration is a very promising way with high performance, but these microporous catalysts are often severely constrained by the rapid catalyst deactivation due to coke formation. Although the introduction of hierarchical structure in microporous zeolite crystals is believed to be an effective approach to enhance their activity and lifetime, the relationship between the mesoporosity and catalytic performance is still controversial. In this paper, four kinds of typical hierarchical ZSM-5 catalysts with diverse mesoporosity and similar microporosity/acidity are prepared by the salt-aided seed-induced route. By systematically studying their catalytic performances, the effects of various mesopore types on the glycerol dehydration are declared, including pore size, amount, distribution, and connectivity. The sample with open and interconnected mesopore architecture display the high activity, long lifetime, and improved selectivity, while the worse behavior of closed and small mesopores is attributed to the mass transfer limitations and/or the in-pore condensation of reactant or its heavier derivatives. Moreover, the combined effect of acidity and hierarchical structure was also explored by changing the framework Si/Al ratio. The findings emphasize the necessity of reasonably designing the zeolite catalysts with proper hierarchical structure and acidity for maximal catalytic advantage.Keywords: acidity; glycerol dehydration; hierarchical structure; structure-performance relationship; zeolite

Hexachlorocyclotriphosphazene and cyanuric chloride are found to be high efficient homogeneous catalysts for dehydration of fructose into 5-hydroxymethylfurfural under mild conditions. The P–Cl or C–Cl bonds play important roles in the reaction, and the strong interaction between the fructose and the electron-withdrawing substituent will help to promote the dehydration.

The catalytic N2O decomposition was investigated over a series of NiCe mixed oxides. Characterizations of XRD, N2-adsorption, SEM, XPS, and H2-TPR were applied to correlate their properties with the corresponding catalytic performance. The catalyst Ni90Ce10 prepared by citrate acid method exhibited the highest catalytic activity among the mixed oxides, which could completely decompose N2O at 400 °C in the presence of oxygen. The introduction of CeO2 could prevent the agglomeration of NiO and preserve high surface area. A strong interaction between NiO and CeO2 was observed in the mixed oxides; the interaction enhanced oxygen mobility and resisted the inhibition of O2.

A novel route for anti-deactivation of methanol-to-propylene catalyst has been established through supporting nano-gold on ZSM-5, which efficiently reinforces the catalytic stability due to the effect of gold nanoparticles on the stabilization of dehydrogenation intermediates within the coking process.

A novel route is proposed for the preparation of mesopore containing zeolite ZSM-5 via in situ hydrothermal treatment of a solution containing alkali-dissolved SBA-15 containing carbonized surfactant P123 in the mesopores; it exhibited prominent stability enhancement for methanol to propylene reaction.

An effective and safe route is proposed to prepare supported Mo2C-based catalysts from organic–inorganic hybrids, which exhibit high activity and stability for producing H2 from methanol catalytic decomposition.

Cu/SiO2 catalysts prepared by the ammonia-evaporation (AE) method have been systematically characterized focusing on the effect of the AE temperature during catalyst preparation. It is found that the texture, composition, and structure of the calcined and reduced Cu/SiO2 catalysts were profoundly affected by the AE temperature. Based on characterizations and previous findings, the copper species on calcined Cu/SiO2 samples and reduced Cu/SiO2 catalysts were assigned. In gas-phase hydrogenation of dimethyl oxalate (DMO) to ethylene glycol (EG), the evolution of the catalytic activity with the Cu0 and Cu+ surface areas suggested that Cu+ also participated in the hydrogenation process. The cooperative effect between Cu0 and Cu+ is proposed to be responsible for the highest hydrogenation activity of the Cu/SiO2 catalyst prepared at the AE temperature of 363 K, on which an EG yield of 98% was obtained under the optimized hydrogenation conditions.

A novel route for anti-deactivation of methanol-to-propylene catalyst has been established through supporting nano-gold on ZSM-5, which efficiently reinforces the catalytic stability due to the effect of gold nanoparticles on the stabilization of dehydrogenation intermediates within the coking process.

A novel route is proposed for the preparation of mesopore containing zeolite ZSM-5 via in situ hydrothermal treatment of a solution containing alkali-dissolved SBA-15 containing carbonized surfactant P123 in the mesopores; it exhibited prominent stability enhancement for methanol to propylene reaction.

An effective and safe route is proposed to prepare supported Mo2C-based catalysts from organic–inorganic hybrids, which exhibit high activity and stability for producing H2 from methanol catalytic decomposition.