With 5 nm Ni nanoparticles anchored by the nanosheet-shaped γ-Al₂O₃ supports, a ~10 wt% Ni/Al₂O₃ catalyst displayed ca. 45% conversion and >98% CH₄ selectivity in CO₂ methanation reaction at 300 °C for 450 h. Benefited from stable interfaces between Ni sites and highly dispersed MnO_x promoters on Al₂O₃, a modified Ni-Mn/Al₂O₃ catalyst exhibited 93–88% conversions, >99.9% selectivity and great stability in 1100 h reaction. As a contrast, a Mo-modified Ni-Mo/Al₂O₃ catalyst showed severe deactivation with declined conversions from >80 to 50% within initial 20 h. The high-dispersion MoO_x species in the fresh catalyst occurred aggregation and reduction during the reaction, reconstructing the Ni-support interfaces. As clarified by in-situ DRIFT spectra, the CO_ads-mediated hydrogenation reaction pathway was followed on these Ni catalysts via sequential steps, CO₂ → bicarbonates → bidentate carbonates → bidentate formates → CO_ads → CH₄. Ni-Mn/Al₂O₃ catalyst exhibited significantly high and well-matched reaction rates in overall steps, whereas Ni/Al₂O₃ catalyst showed low activities in key steps of formate decomposition and CO_ads methanation. Ni-Mo/Al₂O₃ catalyst displayed superior ability for CO₂ dissociation into bicarbonates, and nonetheless, it could not steadily achieve the formation and hydrogenation of CO_ads species, allowing the inactive surface species to be accumulated and to induce the catalyst structural change for deactivation.

使用由纳米片状γ -Al ₂ O ₃载体锚定的 5 nm Ni 纳米颗粒，~10 wt% Ni/Al ₂ O ₃催化剂显示约 在 300°C 450 小时的 CO ₂甲烷化反应中， 45% 的转化率和 >98% 的 CH _{4选择性。}受益于 Ni 位点与Al ₂ O _{3上高度分散的 MnO x}助催化剂之间的稳定界面，改性的 Ni-Mn/Al ₂ O ₃催化剂在 1100 小时反应中表现出 93-88% 的转化率、>99.9% 的选择性和良好的稳定性。作为对比，Mo 改性的 Ni-Mo/Al ₂ O ₃催化剂表现出严重的失活，在最初的 20 小时内转化率从 >80% 下降到 50%。新鲜催化剂中的高分散 MoO _x物种在反应过程中发生聚集和还原，重建了 Ni-载体界面。正如原位 DRIFT 光谱所阐明的，在这些 Ni 催化剂上通过 CO ₂ → 碳酸氢盐 → 双齿碳酸盐 → 双齿甲酸盐 → CO ad _→ CH ₄的顺序步骤在这些 Ni 催化剂上遵循CO _ads介导的加氢反应途径。Ni-Mn/Al ₂ O ₃催化剂在整个步骤中表现出显着高且匹配良好的反应速率，而 Ni/Al ₂ O ₃催化剂在甲酸盐分解和 CO_广告甲烷化的关键步骤中表现出低活性。Ni-Mo/Al ₂ O ₃催化剂表现出优异的 CO ₂解离成碳酸氢盐的能力，但不能稳定地实现 CO 吸附物质的形成和加氢，_导致表面惰性物质积累并诱导催化剂结构更改为停用。