Hydrogenation of cinnamaldehyde to cinnamyl alcohol with metal phosphides: Catalytic consequences of product and pyridine doping
Hydrogenation of cinnamaldehyde to cinnamyl alcohol with metal phosphides: Catalytic consequences of product and pyridine doping
复制标题
DOI：
10.1016/j.apcatb.2020.119272
复制
发表时间：
2020-11-15
影响因子：
22.1
通讯作者：
Hicks, Jason C.
中科院分区：
文献类型：
--
作者：
Bonita, Yolanda;Jain, Varsha;Hicks, Jason C.
由于不饱和官能团（C=C和C=O）与催化剂之间的竞争，α、β不饱和醛的选择性加氢具有挑战性。本研究探讨了金属磷化物作为肉桂醛加氢选择性催化剂的应用。单金属磷化物（MP; M = Ni, Co, Ru）对C=C加氢具有较高的亲和性，Ni2P和Co2P对肉桂醛的选择性为98%。双金属RuMoP提高了肉桂醇（COL）的选择性高达91%，而双金属NiMoP更倾向于C=C加氢而不是氢肉桂醛。密度泛函理论（DFT）表明，表面羰基氧和Mo位点之间的电荷转移较大，导致肉桂醛加氢成COL的活化能势垒较低，而吡啶掺杂研究可能通过表面覆盖效应导致COL的选择性增加。最后，漫反射红外傅里叶变换光谱和DFT为CAL吸附模式和反应机理提供了支持实验观察的见解。
Selective hydrogenation of alpha,beta-unsaturated aldehydes is challenging due to the competition between unsaturated functional groups (C=C and C=O) with the catalyst. This study probes the use of metal phosphides as selective catalysts for cinnamaldehyde hydrogenation. Monometallic phosphides (MP; M = Ni, Co, Ru) showed high affinity to C=C hydrogenation, with 98 % selectivity to hydrocinnamaldehyde with both Ni2P and Co2P. Bimetallic RuMoP improved the cinnamyl alcohol (COL) selectivity up to 91 %, while bimetallic NiMoP preferred C=C hydrogenation to hydrocinnamaldehyde. Density functional theory (DFT) suggested greater charge transfer between the carbonyl oxygen and Mo sites on the surface leading to a lower activation energy barrier for cinnamaldehyde hydrogenation to COL. Product and pyridine doping studies resulted in an increased selectivity to COL possibly through surface coverage effects. Lastly, diffuse reflectance infrared Fourier transform spectra and DFT provided insights into the CAL adsorption mode and the reaction mechanism that supported the experimental observation.