Outstanding efficiency of indium in bimetallic catalysts for hydroconversion of bioacids to bioalcohols
•Indium doped catalysts are highly efficient for acetic acid reduction to ethanol.•Modification with indium resulted in the change of the reaction mechanism.•Turnover frequencies are not dependent on the Pt loading.
Step by step reduction of acetic acid (AA) to ethanol was investigated over novel bimetallic catalysts (PtIn/Al2O3) for the processing of VFAs (volatile fatty acids) that can be produced simply by thermochemical or biological biomass degradation. A fixed bed flow-through reactor was applied with hydrogen stream at 21 bar total pressure in the temperature range of 220–380 °C. AA hydroconversion activity of the parent alumina supported Pt catalyst and the yield of selectively produced alcohol can be increased drastically by In2O3 addition. Appearance of metallic indium creating a bimetallic catalyst can direct the consecutive catalytic reduction to ethanol formation inhibiting hydrodecarbonylation. Comparing the In-containing bimetallic catalysts studied recently, NiIn-catalyst showing similar activity to that of the PtIn-catalyst can be a cheap substitute for the expensive Pt catalysts in the reduction carboxylic acids.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide
Journal: Catalysis Communications - Volume 38, 5 August 2013, Pages 50–53