Synthesis of C Chemicals from CO and H via C-C Bond Formation.

ConspectusThe severity of global warming necessitates urgent CO mitigation strategies. Notably, CO is a cheap, abundant, and renewable carbon resource, and its chemical transformation has attracted great attention from society. Because CO is in the highest oxidation state of the C atom, the hydrogenation of CO is the basic means of converting it to organic chemicals. With the rapid development of H generation by water splitting using electricity from renewable resources, reactions using CO and H have become increasingly important. In the past few decades, the advances of CO hydrogenation have mostly been focused on the synthesis of C1 products, such as CO, formic acid and its derivatives, methanol, and methane. In many cases, the chemicals with two or more carbons (C) are more important. However, the synthesis of C chemicals from CO and H is much more difficult because it involves controlled hydrogenation and simultaneous C-C bond formation. Obviously, investigations on this topic are of great scientific and practical significance. In recent years, we have been targeting this issue and have successfully synthesized the basic C chemicals including carboxylic acids, alcohols, and liquid hydrocarbons, during which we discovered several important new reactions and new reaction pathways. In this Account, we systematically present our work and insights in a broad context with other related reports.1.We discovered a reaction of acetic acid production from methanol, CO and H, which is different from the well-known methanol carbonylation. We also discovered a reaction of C carboxylic acids syntheses using ethers to react with CO and H, which proceeds via olefins as intermediates. Following the new reaction, we realized the synthesis of acetamide by introducing various amines, which may inspire the development of further catalytic schemes for preparing a variety of special chemicals using carbon dioxide as a building block.2.We designed a series of homogeneous catalysts to accelerate the production of C alcohols via CO hydrogenation. In the heterogeneously catalyzed CO hydrogenation, we discovered the role of water in enhancing the synthesis of C alcohols. We also developed a series of routes for ethanol production using CO and H to react with some substrates, such as methanol, dimethyl ether, aryl methyl ether, lignin, or paraformaldehyde.3.We designed a catalyst that can directly hydrogenate CO to C hydrocarbons at 200 °C, not via the traditional CO or methanol intermediates. We also designed a route to couple homogeneous and heterogeneous catalysis, where exceptional results are achieved at 180 °C.