Ni–In Synergy in CO₂ Hydrogenation to Methanol

Indium oxide (In2O3) is a promising catalyst for selective CH3OH synthesis from CO2 but displays insufficient activity at low reaction temperatures. By screening range of promoters (Co, Ni, Cu, and Pd) in combination with In2O3 using flame spray pyrolysis (FSP) synthesis, Ni identified as the most suitable first-row transition-metal promoter similar performance Pd–In2O3. NiO–In2O3 was optimized by varying Ni/In ratio FSP. The resulting catalysts including NiO end members have high specific surface areas morphology. main products hydrogenation are CO CH4 being only observed loading (?75 wt %). highest rate (?0.25 gMeOH/(gcat h), 250 °C, 30 bar) obtained 6 %. Characterization as-prepared reveals strong interaction between cations (?6 H2-TPR points to higher density oxygen vacancy (Ov) due substitution. X-ray photoelectron spectroscopy, absorption electron paramagnetic resonance analysis used suggest that can be reduced single atoms very small clusters during hydrogenation. Supportive functional theory calculations indicate promotion mainly low-barrier H2 dissociation on species, facilitating adsorbed Ov.