This work investigates the promoting effect of Ca on CO₂ hydrogenation to methane in the highly exsolved Ni particles of La_1-xCa_xNiO₃ perovskite catalysts. TEM images presented that metallic Ni particles are exsolved to the surface under a reducing atmosphere. This exsolution behavior is observed until the Ca ratio (x) becomes 0.4, suggesting that the highly dispersed Ni particles formed by the exsolution can actively adsorb and dissociate H₂ molecules. In-situ DRIFTS reveal that the surface Ca-sites effectively adsorb CO₂ molecules to form reactive carbonates species. XPS analyses and CO methanation tests further show that adding Ca negatively charges the adsorption sites and enhances the reactivity of CO. This surface coordination is optimized by incorporating 0.4 of Ca, presenting facile hydrogenation of CO molecules to CH₄. Thus, incorporating 0.4 of Ca into the A-site of LaNiO₃ demonstrated the optimized promoting effect on CO₂ methanation.

这项工作研究了La _1-x Ca _x NiO ₃钙钛矿催化剂中高度溶解的Ni颗粒中Ca对CO ₂加氢成甲烷的促进作用。TEM图像表明，在还原性气氛下，金属Ni颗粒溶解在表面。观察到该析出行为，直到Ca比率（x）变为0.4，这表明由该析出形成的高度分散的Ni颗粒可以有效地吸附和解离H ₂分子。原位DRIFTS显示表面Ca位点有效吸附CO ₂分子形成反应性碳酸盐物质。XPS分析和CO甲烷化测试进一步表明，添加Ca使吸附位带负电荷并增强CO的反应性。通过引入0.4的Ca可以优化表面​​的配位作用，使CO分子易于氢化成CH ₄。因此，将0.4个Ca掺入LaNiO ₃的A位中显示出对CO ₂甲烷化的最佳促进作用。