Sanyal Udishnu, Yuk Simuck F, Koh Katherine, Lee Mal-Soon, Stoerzinger Kelsey, Zhang Difan, Meyer Laura C, Lopez-Ruiz Juan A, Karkamkar Abhi, Holladay Jamie D, Camaioni Donald M, Nguyen Manh-Thuong, Glezakou Vassiliki-Alexandra, Rousseau Roger, Gutiérrez Oliver Y, Lercher Johannes A
Institute for Integrated Catalysis, Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA, 99352, USA.
School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, 97331, USA.
Angew Chem Int Ed Engl. 2021 Jan 4;60(1):290-296. doi: 10.1002/anie.202008178. Epub 2020 Oct 27.
The hydrogenation of benzaldehyde to benzyl alcohol on carbon-supported metals in water, enabled by an external potential, is markedly promoted by polarization of the functional groups. The presence of polar co-adsorbates, such as substituted phenols, enhances the hydrogenation rate of the aldehyde by two effects, that is, polarizing the carbonyl group and increasing the probability of forming a transition state for H addition. These two effects enable a hydrogenation route, in which phenol acts as a conduit for proton addition, with a higher rate than the direct proton transfer from hydronium ions. The fast hydrogenation enabled by the presence of phenol and applied potential overcompensates for the decrease in coverage of benzaldehyde caused by competitive adsorption. A higher acid strength of the co-adsorbate increases the intensity of interactions and the rates of selective carbonyl reduction.
在水中，通过外部电势使苯甲醛在碳负载金属上氢化生成苯甲醇，官能团的极化显著促进了该反应。极性共吸附物（如取代酚）的存在通过两种效应提高了醛的氢化速率，即极化羰基和增加形成氢加成过渡态的概率。这两种效应促成了一种氢化途径，其中苯酚充当质子加成的通道，其速率高于水合氢离子直接转移质子的速率。苯酚的存在和施加的电势所实现的快速氢化，弥补了竞争吸附导致的苯甲醛覆盖度降低。共吸附物较高的酸强度增加了相互作用的强度和选择性羰基还原的速率。
