Ni(OH)₂ Nanosheet as an Efficient Cocatalyst for Improved Photocatalytic Hydrogen Evolution over Cd_0.9Zn_0.1S Nanorods under Visible Light

Loading cocatalysts to promote spatial charge separation has been confirmed as an effective method for improving photocatalytic hydrogen production. This article reports that the synthesis of Ni(OH)2/Cd0.9Zn0.1S nanorod photocatalyst is suitable for photocatalytic H2 generation under visible light. It can be proven that the binary photocatalyst exhibits a one-dimensional nanorod morphological structure. Ni(OH)2 nanosheets occupy the top area of Cd0.9Zn0.1S nanorods. The photocatalytic H2 production rate can reach 132.93 mmol·h–1·g–1, which corresponds to an apparent quantum efficiency of up to 76.5% at a wavelength of 460 nm. In addition, the Ni(OH)2 nanosheet can aggregate the light-incited electrons of Cd0.9Zn0.1S, inhibiting the confluence of electrons and holes. The detailed analysis of its mechanism through characterization methods such as photoluminescence and electrochemical measurement shows that the significant improvement in photocatalytic performance derives from the effective spatial separation of photo-induced charge carriers. Therefore, this synthesis strategy of one-dimensional materials may bring new prospects for more efficient, stable, and sustainable photocatalysis for water splitting

Preparation of Al₂O₃–CeO₂ by Hydrothermal Method Supporting Copper Oxide for the Catalytic Oxidation of CO and C₃H₈

A series of Al2O3–CeO2 carriers were synthesized by hydrothermal method, and CuO/Al2O3–CeO2 catalysts were prepared by ultrasound-assisted impregnation for the catalytic oxidation of CO and C3H8. These prepared samples have been characterized by XRD, BET, TEM, XPS, and other techniques. The 15 wt % CuO/A1C1 catalyst exhibited the best catalytic activity, and the light-off temperatures (T50) of CO and C3H8 were 67 and 325 °C, respectively. XRD results showed that the dispersion of CuO on the catalyst surface was improved by the introduction of CeO2 into the CuO/Al2O3 catalyst. Besides, with the addition of CeO2 content, the specific surface area and pore volume of the sample gradually decrease. XPS results suggest that the synergistic effect (Ce3+ + Cu2+ ↔ Ce4+ + Cu+) is conducive to the generation of oxygen vacancies and improves the activity of the catalyst. Both H2-TPR and O2-TPD temperatures shift toward lower temperatures, indicating that redox reactions are more likely to occur. Finally, based on the results of in situ DRIFTS, the surface Cu+ species obtained from the reduction of Cu2+ play a crucial role in the catalytic oxidation of CO and C3H8

Hydrothermal Synthesis of a Ce–Zr–Ti Mixed Oxide Catalyst with Enhanced Catalytic Performance for a NH₃‑SCR Reaction

A series of mesoporous CeZrTiOx catalysts were prepared by a facile hydrothermal method. Compared with CeTiOx catalysts synthesized under the same conditions, the catalytic activity and anti-SO2 performance of the Ce1Zr1TiOx catalyst are greatly improved, and at the gas hourly space velocity (GHSV) of 60 000 h–1, the NOx removal efficiency is maintained at 90% in the temperature range of 290–500 °C. The catalytic effect of ZrO2 on the Ce–Ti catalyst NH3-SCR activity was elucidated through a series of characterizations. The results revealed that the doping of Zr could significantly improve and optimize the structure of Ce–Ti catalysts. At the same time, due to the doping of Zr, the synergistic effect between Ce and Zr in the CeZrTiOx catalyst can effectively increase oxygen mobility, total acid content, and surface adsorbed oxygen species and lead to a larger pore volume. In addition, the introduction of ZrO2 made the transformation of Ce4+ into Ce3+ more obvious, and the 2Ce4+ + Zr2+ ↔ 2Ce3+ + Zr4+ reaction greatly improved the reducibility of Ce1Zr1TiOx. Among them, the improvement of SCR performance and H2O/SO2 tolerance is due to the electronic interaction between Zr and Ce

Design and Synthesis of Palladium/Black Phosphorus–Graphene Hybrids as High-Performance Catalysts for Ethanol Electrooxidation in Alkaline Media

In this study, a series of Pd-supported black phosphorus–graphene (Pd/BP-G) catalysts are prepared to explore their electrocatalytic performances in the electrooxidation of ethanol in alkaline media. The characterization results show that BP is combined with activated graphene to form a P–C bond and a P–O–C bond heterojunction. Pd nanoparticles equally anchor on the BP-G hybrid, and Pd/BP-G exhibited enhanced electrocatalytic activity for the ethanol oxidation reaction in alkaline media. The electrochemically active surface area and mass activity for the Pd/BP-G catalyst reached 210.4 m2·gPd–1 and 3960.0 mA·mgPd–1, which are 9.54 and 5.86 times higher than those of commercial Pd/C, respectively. Further studies show that Pd/BP-G catalysts have reliable stabilities and faster reaction kinetics. These results indicate that the prepared Pd/BP-G catalysts have great application potentials in direct ethanol fuel cells

Preparation of Ce_<i>x</i>Zr_1–<i>x</i>O₂ by Different Methods and Its Catalytic Oxidation Activity for Diesel Soot

Novel CexZr1–xO2 (x = 0.67, 0.8, 0.9, 1.0) catalysts were designed and synthesized by solvothermal, calcination, and sol–gel methods and were used to catalyze oxidation of soot from diesel vehicle exhaust. The influence of catalysts synthesized by different methods and Ce/Zr molar ratios on the performance was investigated. These catalysts were characterized by XRD, N2 adsorption–desorption, FT-IR, TEM, XPS, H2-temperature programmed reduction (TPR), and O2-temperature programmed desorption (TPD) techniques. The results indicated that Ce0.8Zr0.2O2 prepared by the calcination method has excellent activity and stability at low temperature. The soot ignition point is 322 °C, and the ratio of soot conversion reaches 90% at 497 °C, which is lower than that from the solvothermal and sol–gel methods. The XRD, Raman, SEM, XPS and H2-TPR results reveal that the structure and oxygen adsorption properties are crucial to soot oxidation activity, and Zr4+ is successfully doped into the CeO2 lattice and forms a homogeneous solid solution. Nanostructured Ce0.8Zr0.2O2 with 110.2 m2/g surface areas is produced. The proportion of chemical oxygen and surface adsorbed oxygen in the catalyst prepared from the calcination method is the highest at 23.18%. The structure may lead to charge imbalance, unsaturated bonds, and oxygen vacancies, thus increasing the adsorption of oxygen on the catalyst surface