Unique CO₂ methanation catalysts comprising bimetallic Ni–Rh nanoalloy/3DOM LaAlO₃ have been successfully prepared via a poly(methyl methacrylate) microsphere colloidal crystal-templating route, followed by the in situ growth of Ni nanoparticles (NPs). Here, we show that unlike traditional Ni particles deposited on a perovskite support, the exsolution of Ni occurs on both the external and internal surface of the porous perovskite substrate, leading to a strong metal–support interaction. Owing to the exsolution of Ni and the formation of Ni–Rh nanoalloys, a 52% enhancement in the methanation turnover frequency was obtained over the Ni–Rh/3DOM LaAlO₃ [13.9 mol/(mol h)] compared to Rh/3DOM LaNi_0.08Al_0.92O₃ [9.16 mol/(mol h)] before reduction treatment. The results show that the low-temperature reducibility, rich surface adsorbed oxygen species, and basic sites of the catalyst greatly improve its activity toward CO₂ methanation. The hierarchically porous structure of the perovskite support provides a high dispersion of bimetallic Ni–Rh NPs.

中文翻译：

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双金属Rh-Ni纳米合金的原位析出：高效的CO ₂甲烷化催化剂

已通过聚（甲基丙烯酸甲酯）微球胶体晶体模板路线成功地制备了包含双金属Ni-Rh纳米合金/ 3DOM LaAlO _3的独特CO ₂甲烷化催化剂，然后原位生长Ni纳米颗粒（NPs）。在这里，我们表明，与沉积在钙钛矿载体上的传统Ni颗粒不同，Ni的析出发生在多孔钙钛矿衬底的内外表面上，从而导致强烈的金属-载体相互作用。由于Ni的析出和Ni-Rh纳米合金的形成，与Rh / 3DOM LaNi相比，Ni-Rh / 3DOM LaAlO ₃ [13.9 mol /（mol h）]的甲烷化转换频率提高了52％。_0.08铝_0.92 O还原处理前为₃ [9.16 mol /（mol h）]。结果表明，催化剂的低温还原性，丰富的表面吸附氧种类和碱性位点大大提高了其对CO ₂甲烷化的活性。钙钛矿载体的分层多孔结构提供了双金属Ni-Rh NPs的高分散性。