Lima Fernanda Alves, Bezerra Marco A M, Souza Rodrigo, Itabaiana Ivaldo, Haynes Tommy, Hermans Sophie, Wojcieszak Robert, Novaes Fábio Junior M, Rezende Claudia Moraes
Instituto de Química, Universidade Federal do Rio de Janeiro, Avenida Athos da Silveira Ramos, 149, Bloco A - 626a, 21941-909 Rio de Janeiro, Brazil.
Escola de Quimica, Departamento de Engenharia Bioquímica, Universidade Federal do Rio de Janeiro, Athos da Silveira Ramos, 149, Cidade Universitária, 21941-895 Rio de Janeiro, Brazil.
ACS Omega. 2020 Sep 28;5(40):25712-25722. doi: 10.1021/acsomega.0c01835. eCollection 2020 Oct 13.
This work investigates batch and continuous-flow heterogeneous catalytic hydrogenation of a mixture of cafestol and kahweol (C&K) to obtain pure cafestol. These diterpenes were extracted from green coffee beans, and hydrogenation was performed using well-established palladium catalysts (Pd/C, Pd/CaCO, Pd/BaSO, and Pd/AlO) and a carbon black-supported Pd catalyst coated by a covalently tethered SiO shell with mesoporous texture (Pd/CB@SiO), all partially deactivated with quinoline. Pd/C 10% poisoned with 1 wt % quinoline gave the best result for batch reaction, producing cafestol from kahweol with high selectivity (>99%) after 10 min. Excellent selectivity was also obtained with the catalyst Pd/CB@SiO with only 1% Pd. In addition, Pd/C-quinoline adapted for continuous-flow experiments exhibited the best catalytic activity, also providing cafestol with excellent selectivity (>99%) after 9.8 s.
本研究考察了咖啡豆醇和卡维醇（C&K）混合物的间歇式和连续流多相催化氢化反应，以获得纯咖啡豆醇。这些二萜类化合物从生咖啡豆中提取，氢化反应使用成熟的钯催化剂（Pd/C、Pd/CaCO、Pd/BaSO和Pd/AlO）以及一种由具有介孔结构的共价连接SiO壳包覆的炭黑负载钯催化剂（Pd/CB@SiO）进行，所有催化剂均用喹啉部分失活。用1 wt%喹啉中毒的10% Pd/C在间歇反应中给出了最佳结果，10分钟后从卡维醇中生产咖啡豆醇的选择性很高（>99%）。仅含1% Pd的催化剂Pd/CB@SiO也获得了优异的选择性。此外，适用于连续流实验的Pd/C-喹啉表现出最佳的催化活性，在9.8秒后也能提供选择性优异（>99%）的咖啡豆醇。
