PdIn intermetallic nanoparticles for the Hydrogenation of CO2 to Methanol

作者：Andrés García‐Trenco, Anna Regoutz, Edward R. White, David J. Payne, Milo S. P. Shaffer, Charlotte K. Williams · 发表于：Applied Catalysis B: Environmental · 年份：2017 · DOI：10.1016/j.apcatb.2017.07.069 · 被引用次数：228 · 研究领域：Catalysts for Methane Reforming、Catalytic Processes in Materials Science、Nanomaterials for catalytic reactions

Direct hydrogenation of CO 2 to methanol could offer significant environmental benefits, if efficient catalysts can be developed. Here, bimetallic Pd-In nanoparticles show good performance as catalysts for this reaction. Unsupported nanoparticles are synthesised by the thermal decomposition of Pd(acetate) 2 and In(acetate) 3 precursors in a high boiling point solvent (squalane), followed by reduction using dilute H 2 gas (210 °C). Adjusting the ratio of the two metallic precursors allow access to 5–10 nm nanoparticles with different phase compositions, including metallic Pd(0), In 2 O 3 and intermetallic PdIn. Liquid phase methanol synthesis experiments (50 bar, 210 °C, H 2 :CO 2 = 3:1) identify the intermetallic PdIn nanoparticles as the most efficient. The catalysts exhibit around 70% higher methanol rates (normalised to the overall molar metal content) compared to the conventional heterogeneous Cu/ZnO/Al 2 O 3 catalyst (900 and 540 μmol mmol PdInorCuZnAl −1 h −1 , respectively). In addition, the optimum Pd/In catalyst shows an improved methanol selectivity over the whole temperature range studied (190–270 °C), reaching >80% selectivity at 270 °C, compared to only 45% for the reference Cu/ZnO/Al 2 O 3 catalyst. Experiments showed an improvement in stability; the methanol production rate declined by 20% after 120 h run for the optimum PdIn-based compared with 30% for the Cu/ZnO/Al 2 O 3 catalyst (after 25 h). The optimum catalyst consists of ∼8 nm nanoparticles comprising a ...