CO2 hydrogenation to ethanol over Pt-Co3O4 catalysts: Effects of Pt promoter

Abstract

Direct hydrogenation of CO₂ to ethanol is a promising approach for utilizing CO₂. However, it still faces challenges such as lower selectivity and unclear C-C coupling mechanisms. In this work, we prepared Co₃O₄ catalysts and Pt-loaded Co₃O₄ catalysts (Pt-Co₃O₄) to investigate the influence of Pt on the properties of Co₃O₄ catalysts and the CO₂ hydrogenation process. At 240°C and 3.2 MPa, the reduced 1wt. % Pt-Co₃O₄ catalyst showed 0.265 mmol/(g·h) ethanol yield, while the ethanol yield of the reduced Co₃O₄ catalyst was negligible. The characterization results revealed that the presence of Pt facilitated the regeneration of oxygen vacancies on the catalyst surface, leading to enhanced cycling performance. The in-situ DRIFTS results demonstrated that the *OCH₃ generated on the Pt-Ov site underwent coupling with the *CH₃ generated on the Co site, leading to ethanol production.