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CO2 hydrogenation to methane, namely, CO2 methanation or Sabatier reaction, is a significant approach to convert CO2 and H2 to storable and transportable CH4. Low reaction temperature is the key to industrialization and has attracted plenty of research interest. Ni-based catalysts are commonly utilized owing to their favorable properties of excellent activity and economical price. However, it is still challenging to perform the Sabatier reaction under temperatures lower than 300 °C owing to the inertness of CO2. Hence, in this article, we summarize the advances of four important design principles of the Ni-based catalysts for low-temperature Sabatier reaction, namely, optimizing Ni active sites, tuning support properties, considering metal–support interactions, and choosing a suitable preparation method, which provides deep insights for the design of low-temperature CO2 methanation catalysts. Additionally, typical low-temperature CO2 methanation reaction mechanisms with *CO or *HCOO as the main intermediate and perspectives on this topic have been provided. We highlight that the rare-earth oxide-supported Ni-based catalysts with the potential reaction mechanism and corresponding reactor design would be promising for low-temperature Sabatier reaction. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation to methane (also known as "CO2 methanation") is an important way to achieve the goal of carbon neutralization. CeO2 is considered as one of the most important catalyst supports because of its abundant surface oxygen vacancies and excellent oxygen storage capacity. Transition metal Ni is also widely studied because of its excellent catalytic performance and low price. The Ni/CeO2-based catalysts formed by the combination of CeO2 and metal Ni show good application prospects in CO2 methanation. The reaction mechanisms of Ni/CeO2-based catalysts for CO2 methanation were summarized and the preparation methods of Ni/CeO2-based catalysts were introduced, and the key parameters affecting catalytic performance of CO2 methanation such as the characteristics of active centers, properties of supports, types of additives and metal-support interactions were summarized, and the catalytic performances of Ni/CeO2-based catalysts were also summarized. It is found that by modifying Ni/CeO2-based catalysts, the catalytic performances and product selectivities of Ni/CeO2-based catalysts for CO2 methanation can be regulated, which can provide new ideas for improving their catalytic performances of CO2 methanation. [ABSTRACT FROM AUTHOR]

H2O adsorption plays a pivotal role in the initial stages of methanol steam reforming (MSR), significantly influencing the subsequent reactions on the catalyst surface. In this work, periodic DFT + U + D3 calculations were employed to investigate the adsorption of H2O on perfect and O-defective CuAlO2(112¯0) catalysts. The results reveal that the role of oxygen vacancies (Ov) in promoting H2O dissociative adsorption is particularly pronounced at low coverage, diminishing as coverage increases. Within increasing the surface coverage (nH2O, n = 1–18) on the perfect surface, the H2O molecule undergoes three adsorption stages, dissociative, molecular, and physisorption, involving the formation of four types of hydrogen bonds: (i) between OwH* and OsH (n = 1–6), (ii) between molecularly adsorbed H2O and surface O (n = 7–12), (iii) between physiosorbed H2O and surface O (n = 13–18), and (iv) between physiosorbed H2O and molecularly adsorbed H2O (n = 13–18). Notably, oscillatory behavior of type-i hydrogen bonds induced by geometric effects of incoming H2O molecules is observed in the 7–12 coverage range, along with the elimination of type-ii hydrogen bonds at the 12–13 coverage. The phase diagram of H2O adsorption under typical MSR conditions indicates that the surface coverage falls within the 7–12H2O range, providing crucial insights for understanding the surface nature to optimize MSR over CuAlO2 catalysts. Our results highlight that the number and type of hydrogen bonds significantly impact H2O adsorption energy, with low coverage H2O activation being facilitated by Ov, thereby promoting the initial stage of MSR over CuAlO2. [ABSTRACT FROM AUTHOR]

Bimetallic catalysts have widespread applications in many reactions. Series of Ni/SiO2 catalysts containing different promoters were prepared by ammonia evaporation method in this work. The effect of Sn and Mg additives on the catalytic performance of nickel-based catalysts in acetylene hydrogenation was investigated. The introduction of Mg additives led to the over-hydrogenation of acetylene to ethane, vs. the Sn promoter increases the selectivity of the catalysts towards ethylene. The Ni7Sn/SiO2 showed the most superior catalytic performance. The effects of different additives on the active metals were investigated through a series of characterizations and thus the structure-performance relationship was well investigated. Reaction mechanism diagram of acetylene and hydrogen over Ni/SiO2 based catalysts. [ABSTRACT FROM AUTHOR]

CO2 hydrogenation to chemicals and fuels is a significant approach for achieving carbon neutrality. It is essential to rationally design the chemical structure and catalytic active sites towards the development of efficient catalysts. Here we show a Ce-CuZn catalyst with enriched Cu/Zn-OV-Ce active sites fabricated through the atomic-level substitution of Cu and Zn into Ce-MOF precursor. The Ce-CuZn catalyst exhibits a high methanol selectivity of 71.1% and a space-time yield of methanol up to 400.3 g·kgcat−1·h−1 with excellent stability for 170 h at 260 °C, comparable to that of the state-of-the-art CuZnAl catalysts. Controlled experiments and DFT calculations confirm that the incorporation of Cu and Zn into CeO2 with abundant oxygen vacancies can facilitate H2 dissociation energetically and thus improve CO2 hydrogenation over the Ce-CuZn catalyst via formate intermediates. This work offers an atomic-level design strategy for constructing efficient multi-metal catalysts for methanol synthesis through precise control of active sites. Carbon dioxide hydrogenation is an important industrial reaction. Here, the authors design a CeCuZn catalyst through a metal organic framework template for CO2 hydrogenation to methanol with excellent methanol yield and stability. [ABSTRACT FROM AUTHOR]

The ammonia-evaporation method is one of the most commonly methods for preparing Cu–SiO2 catalysts, and the improvement of this method is desirable. This work showed that it could improve the catalytic performance of the Cu–SiO2 catalyst in the hydrogenation of dimethyl oxalates (DMO) to ethylene glycol by introducing hydrothermal aging process and adjusting the aging time after evaporated ammonia. There was no obvious effect on copper phyllosilicate formation with the hydrothermal aging time increasing, but it affected the dispersion of Cu0 species among the copper phyllosilicate layers. As the number of Cu0 species is enough on the catalyst surface, the density of surface Cu0 species would affect the synergistic effect between Cu0 and Cu0 active sites. It is possible that the DMO absorbed on the Cu+ species would be inhibited while the density of surface Cu0 species is highly. Thus, the modified Cu–SiO2 catalyst by hydrothermal aging process with relatively low Cu0 dispersion exhibited enhanced catalytic performance in DMO catalytic hydrogenation. [ABSTRACT FROM AUTHOR]

Rational design of low‐cost and efficient transition‐metal catalysts for low‐temperature CO2 activation is significant and poses great challenges. Herein, a strategy via regulating the local electron density of active sites is developed to boost CO2 methanation that normally requires >350 °C for commercial Ni catalysts. An optimal Ni/ZrO2 catalyst affords an excellent low‐temperature performance hitherto, with a CO2 conversion of 84.0 %, CH4 selectivity of 98.6 % even at 230 °C and GHSV of 12,000 mL g−1 h−1 for 106 h, reflecting one of the best CO2 methanation performance to date on Ni‐based catalysts. Combined a series of in situ spectroscopic characterization studies reveal that re‐constructing monoclinic‐ZrO2 supported Ni species with abundant oxygen vacancies can facilitate CO2 activation, owing to the enhanced local electron density of Ni induced by the strong metal‐support interactions. These findings might be of great aid for construction of robust catalysts with an enhanced performance for CO2 emission abatement and beyond. [ABSTRACT FROM AUTHOR]

The development of efficient and low‐cost bifunctional catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is imperative but remains challenging in rechargeable zinc–air batteries. Herein, a metal oxidation‐assisted approach is developed for the facile synthesis of a highly efficient bifunctional catalyst (Co@NC@LDHs) which is composed of layered double hydroxides (LDHs) nanosheets in situ vertically grown on the surface of hollow carbon nanoframes encapsulating Co nanoparticles (Co@NC). Specifically, the vertical LDHs distributing on the carbon surface ensure the maximized number of accessible active sites and the interaction between LDHs with the carbon matrix. The hierarchically structured bifunctional Co@NC@LDHs display an overpotential of 0.33 V at 10 mA cm−2 for OER and a half‐wave potential of 0.88 V for ORR. The potential gap (ΔE) of Co@NC@LDHs is calculated to be 0.68 V, outperforming the mixed Pt/C + RuO2 catalysts (ΔE = 0.77 V), manifesting its superior bifunctional electrocatalysis performance. Moreover, the Zn–air batteries based on Co@NC@LDHs electrocatalyst exhibit a high peak power density (185.2 mW cm−2) and excellent durability (5.0 mA cm−2 over 500 h). This work may provide a facile strategy for the fabrication of LDHs on carbon substrate, acting as efficient catalysts for broad energy‐related applications. [ABSTRACT FROM AUTHOR]