The Catalytic Reduction of Carboxylic Acid Derivatives and CO2 by Metal Nanoparticles on Lewis‐Acidic Supports

The development of heterogeneous catalysts for green chemical synthesis is currently a growing area in catalysis and sustainable chemistry. Especially the use of renewable carbon resources such as carbon dioxide (CO2) and biomass‐derived compounds (e. g. carboxylic acids, esters, and amides) represent highly attractive research targets. As these substances reside in a high oxidation state, efficient reduction processes are required in order to convert these substrates into useful and value‐added chemicals. Moreover, in the interest of mass production, these substrates should be reduced by molecular H2 and a heterogeneous catalyst. In this context, our group has developed advanced catalysts and established design guidelines for catalysts that promote the reductive transformations of carboxylic acid derivatives and CO2. Our studies show that cooperative catalysis between Lewis‐acidic sites on the catalyst support and supported metal nanoparticles are crucial for the success of these challenging hydrogenations. In this review, we summarize the results of our recent studies on the direct synthesis of value‐added chemicals from CO2 and carboxylic acid derivatives using supported transition‐metal catalysts, and we propose a design concept for heterogeneous catalysts that promote these processes. The cooperative catalysis of Lewis‐acidic metal oxides and metallic Pt nanoparticles for a variety of challenging hydrogenation processes are reviewed. The underlying reaction mechanisms and structure‐activity relationships are discussed in order to develop a design guidelines for advanced multifunctional heterogeneous catalysts.