NiPt catalysts for the synthesis of iso-butanol: the influence of molar ratio and total metal loading on activity and stability†

If methanol and ethanol are produced regeneratively from green H₂ and CO₂, a mixture of these two can further react to form longer-chain branched alcohols such as iso-butanol, which can serve as sustainable feedstocks for the transportation and chemical sectors. NiPt catalysts have shown to be promising for this process. This study investigates the influence of the total metal loading Ni + Pt and the molar ratio of Ni to Pt on catalytic behavior. It was observed that the values for the total metal loading and the molar fraction of Pt must be set correctly and precisely during synthesis, as most of all the space–time yield of the catalyst, the conversion of ethanol, and the iso-butanol yield strongly depend on them. Differing mechanisms for the decomposition of acetaldehyde on pure Pt/C and NiPt/C are comparatively discussed. They explain the beneficial effect of Ni in avoiding the formation of carbonaceous deposits on the active centers. In addition, Ni was found to prevent particle growth due to its strong metal–support interaction.