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Ni component can be effectively introduced into CeO2 by a soft template method to prepare porous NiCe composite catalysts. The reducibility of the catalyst precursors was studied by H2‐TPR. The physicochemical properties of the prepared NiCe composite catalysts were characterized by XRD, quasi in‐situ XPS, BET and TEM. And the catalytic performances of the corresponding NiCe composite catalysts was evaluated by CO2 catalytic hydrogenation. The synergistic effect of Ni and Ce species can significantly improve the reducibility of the precursors to form CO2 hydrogenation active sites in the corresponding NiCe composite catalysts. The morphology, pore structure, specific surface area, crystallinity and content of metal Ni species of the prepared NiCe composite catalysts were significantly affected by nNi/nCe ratio, which can affect the CO2 catalytic hydrogenation performances of NiCe composite catalysts. The synergistic effect of Ni and Ce species can also promote the formation of NiCe composite catalyst nanoparticles with small particle size about 5–10 nm. The developed mesoporous structure and high specific surface area can be formed in the prepared NiCe composite catalysts. The NC3 catalyst with a nNi/nCe ratio of 3.0 showed the best CO2 hydroreduction performances and use stability. When the reaction temperature was 300 °C, the CO2 conversion and CH4 selectivity can reach 85.6% and 100%, respectively. Even if the reaction temperature rises to 340 °C, the CO2 conversion and CH4 selectivity can be maintained at 83.7% and 100% in the continuous reaction of 600 min, respectively. [ABSTRACT FROM AUTHOR]

Pd/CeO2 catalysts with different metallic Pd loading were synthesized by impregnation method. The physicochemical properties of prepared Pd/CeO2 catalysts and corresponding precursors were studied by XRD, XPS, H2-TPD and H2-TPR. Moreover, the catalytic performance of the Pd/CeO2 catalysts was investigated via gas phase benzene hydrogenation reaction at the temperature of 100–200 °C under atmosphere pressure. Results show that the catalytic performance of prepared Pd/CeO2 catalysts is directly related to the metallic Pd content. The amounts of active metallic Pd and adsorbed-desorbed hydrogen species on Pd/CeO2 catalysts increase with the increasing metallic Pd loading from 1.0 to 3.0%, while the numbers of them are slightly reduced on Pd/CeO2(3.5) catalyst. Furthermore, metallic Pd is highly dispersed on the nano-CeO2 supports, therefore, the prepared Pd/CeO2 catalysts present good gas phase benzene catalytic hydrogenation performance. At 200 °C, the benzene conversion over the Pd/CeO2 catalysts with different metallic Pd loading follows the rule: Pd/CeO2(3.0) > Pd/CeO2(3.5) > Pd/CeO2(2.5) > Pd/CeO2(2.0) > Pd/CeO2(1.5) > Pd/CeO2(1.0), corresponding values are 94.3, 96.4, 89.9, 82.8, 72.7, 42.6 and 94.3%. And the cyclohexane selectivity is 100% on all prepared Pd/CeO2 catalysts. [ABSTRACT FROM AUTHOR]

Supported Co/KIT‐6 catalyst, which has high specific surface area and well‐developed ordered mesoporous structure, was prepared by wet impregnation method. Its physicochemical properties were characterized by transmission electron microscopy (TEM), Brunner–Emmet–Teller (BET), Low‐angle XRD, in situ X‐ray photoelectron spectroscopy (in situ XPS) and H2‐temperature program reduction (H2‐TPR), and its catalytic properties were investigated by CO2 hydrogenation. The in situ XPS and H2‐TPR results indicated that Co oxide species could be reduced by H2 to highly dispersed active metal Co species. The highly dispersed active metal Co species are the main CO2 hydrogenation active centers. CO2 molecules could be reduced by active metal Co species to generate CO molecules and promote CO2 methanation. The prepared Co catalyst presented high CO2 catalytic hydrogenation activities and stability. The CO2 conversion exceeds 47%, and CO and CH4 selectivity reaches 25.6% and 74.4% at 400°C within the range of reaction time of 500 min, respectively. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The mesoporous Ni/KIT-6 catalysts with different composition were prepared by altering reduction temperatures. In addition, their physicochemical properties were characterized by X-ray diffraction, in-situ X-ray photoelectron spectroscopy, and Brunauer–Emmett–Teller techniques. The results shown that the specific surface area, composition and metallic Ni crystallinity of the Ni/KIT-6 catalyst were significantly affected by reduction temperatures. The catalytic performances of the prepared Ni/KIT-6 catalysts were evaluated via the CO2 reforming of CH4 into syngas and followed the order: RT0 < RT250 < RT300 < RT350 < RT400 < RT450 ≈ RT500. The specific surface area, pore volume, pore diameter, and Ni0 content of the most representative RT450 catalyst among of them were 646.7 m2 g−1, 0.92 cm3 g−1, 6.5 nm, and 30.9%, respectively. The CH4 and CO2 conversions of RT450 catalyst reached to 69.0 and 39.4% under a reaction temperature of 600 °C, respectively. The CO selectivity was greater than 49% and the RT450 catalyst had good stability. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation for syngas can alleviate the pressure of un‐controlled emissions of CO2 and bring enormous economic benefits. Advantageous Ni‐catalysts have good CO2 hydrogenation activity and high CO selectivity merely over 700 °C. Herein, we introduced Cu into Ni catalysts, which were evaluated by H2‐TPR, XRD, BET, in‐situ XPS and CO2‐TPD, and their CO2 hydrogenation activity and CO selectivity were significantly affected by the Ni/Cu ratios, which was rationalized by the synergistic effect of bimetallic catalysts. In addition, the reduction temperatures of studied catalysts apparently affected the CO2 hydrogenation, which were caused by the number and dispersion of the active species. It's found that the Ni1Cu1‐400 had good stability, high CO selectivity (up to 90%), and fast formation rate (1.81×10−5 mol/gcat/s) at 400 °C, which demonstrated a good potential as a superior catalyst for reverse water‐gas shift (RWGS) reaction. [ABSTRACT FROM AUTHOR]

The Co–C3N4/BiPO4 photocatalyst is facilely synthesized for application in photocatalytic water splitting. The physical and chemical properties of Co–C3N4/BiPO4 are studied by a wide range of characterization methods. The Co–CN/BP photocatalyst shows good photocatalytic activity for H2 evolution by water splitting without using a noble metal. The Co–C3N4/BiPO4 composite with 5 wt% Co–C3N4 loading exhibits a superior photocatalytic H2 evolution rate of 23.9 μmol h−1 g−1. The remarkable enhancement of the photocatalytic H2 evolution activity of Co–C3N4/BiPO4 composites is mainly ascribed to the effective charge transfer and separation of the electron–hole pairs by the lattice-matched heterojunction structure. This work extends opportunities for the design of non-noble metal photocatalysts with efficient photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

Different proportions (0, 1%, 3%, 5%, 7%, 9wt%) of hierarchical g-C3N4/SnO2 heterostructures were synthesized by one-step hydrothermal method. The crystal structure, morphology and optical properties of the materials were investigated by X-ray diffraction (XRD), infrared spectroscopy (FT-IR), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS), electron microscopy (SEM and TEM), BET specific surface area measurement and photoluminescence spectroscopy (PL). Meanwhile, the gas sensing performances of g-C3N4/SnO2 nanostructures were investigated towards ethanol. The results showed that the gas response of 5wt% g-C3N4/SnO2 based sensor was 77.5 x 10-6 to 40 x 10-6 ethanol at the optimum working temperature of 270 °C, which was about 8.4 times higher than that of the pure SnO2. Finally, the enhanced gas sensing mecha nism of the g-C3N4/SnO2 nanocomposite was discussed. [ABSTRACT FROM AUTHOR]

In this work, we report a facile and controllable method to enhance the catalytic activity and stability of Mo2C–C for CO2 hydrogenation by incorporating N-functional groups on the interface of Mo2C–C to simultaneously serve as basic sites for improving CO2 chemisorption and to immobilize copper particles to prevent aggregation. The incorporated N changed the surface chemical environment of Mo2C and Cu, resulting in the coexistence of Cu2+/Cu+/Cu0 and electron transfer from the copper to the molybdenum species (via MoOxCy–□–Cu+/Cu0). The strong coupling effects of N, Mo2C, and Cu on Cu–Mo2C–N–C is beneficial for further enhancing the adsorption and activation of CO2 and H2 molecules. Accordingly, the Cu–Mo2C–N–C catalysts exhibit greatly superior catalytic activity and stability toward CO2 hydrogenation compared with other catalysts. This facile method may be extended to other materials-based interface engineering to fabricate efficient CO2 hydrogenation catalysts. [ABSTRACT FROM AUTHOR]

CeO catalysts with different structure were prepared by hard-template (Ce-HT), complex (Ce-CA), and precipitation methods (Ce-PC), and their performance in CO reverse water gas shift (RWGS) reaction was investigated. The catalysts were characterized using XRD, TEM, BET, H-TPR, and in-situ XPS. The results indicated that the structure of CeO catalysts was significantly affected by the preparation method. The porous structure and large specific surface area enhanced the catalytic activity of the studied CeO catalysts. Oxygen vacancies as active sites were formed in the CeO catalysts by H reduction at 400 °C. The Ce-HT, Ce-CA, and Ce-PC catalysts have a 100% CO selectivity and CO conversion at 580 °C was 15.9%, 9.3%, and 12.7%, respectively. The highest CO RWGS reaction catalytic activity for the Ce-HT catalyst was related to the porous structure, large specific surface area (144.9 m∙g) and formed abundant oxygen vacancies. [ABSTRACT FROM AUTHOR]