Enhancing the intrinsic activity and space time yield of Cu based heterogeneous methanol synthesis catalysts through CO₂ hydrogenation is one of the major topics in CO₂ conversion into value-added liquid fuels and chemicals. Here we report inverse ZrO₂/Cu catalysts with a tunable Zr/Cu ratio have been prepared via an oxalate co-precipitation method, showing excellent performance for CO₂ hydrogenation to methanol. Under optimal condition, the catalyst composed by 10% of ZrO₂ supported over 90% of Cu exhibits the highest mass-specific methanol formation rate of 524 g_MeOHkg_cat⁻¹h⁻¹ at 220 °C, 3.3 times higher than the activity of traditional Cu/ZrO₂ catalysts (159 g_MeOHkg_cat⁻¹h⁻¹). In situ XRD-PDF, XAFS and AP-XPS structural studies reveal that the inverse ZrO₂/Cu catalysts are composed of islands of partially reduced 1–2 nm amorphous ZrO₂ supported over metallic Cu particles. The ZrO₂ islands are highly active for the CO₂ activation. Meanwhile, an intermediate of formate adsorbed on the Cu at 1350 cm⁻¹ is discovered by the in situ DRIFTS. This formate intermediate exhibits fast hydrogenation conversion to methoxy. The activation of CO₂ and hydrogenation of all the surface oxygenate intermediates are significantly accelerated over the inverse ZrO₂/Cu configuration, accounting for the excellent methanol formation activity observed.

Reversing the thermal induced sintering phenomenon and forming high temperature stable fine dispersed metallic centers with unique structural and electronic properties is one of the ever-lasting targets of heterogeneous catalysis. Here we report that the dispersion of metallic Ni particles into under-coordinated two-dimensional Ni clusters over γ-Mo₂N is a thermodynamically favorable process based on the AIMD simulation. A Ni-4nm/γ-Mo₂N model catalyst is synthesized and used to further study the reverse sintering effect by the combination of multiple in-situ characterization methods, including in-situ quick XANES and EXAFS, ambient pressure XPS and environmental SE/STEM etc. The under-coordinated two-dimensional layered Ni clusters on molybdenum nitride support generated from the Ni-4nm/γ-Mo₂N has been demonstrated to be a thermally stable catalyst in 50 h stability test in CO₂ hydrogenation, and exhibits a remarkable catalytic selectivity reverse compared with traditional Ni particles-based catalyst, leading to a chemo-specific CO₂ hydrogenation to CO.