醇和氢硅烷之间的脱氢偶联反应被认为是生产Si-O偶联化合物的最原子经济的方法之一,因为其副产物仅为氢气(H2),这使得它非常环保。在过去的几十年里,用于醇和氢硅烷脱氢偶联的各种均相催化剂,如过渡金属络合物,碱土金属,碱金属,和贵金属络合物,已经报道了它们良好的活性和选择性。然而,这些催化剂的实际应用仍然不尽人意,这主要受到环境影响和不可重用性的限制。一种简便且可回收的非均相催化剂,超小Ag纳米颗粒负载在多孔碳(Ag/C)上,用于硅烷的醚化,已经开发了。对Si-O偶联反应具有较高的催化活性,反应的表观活化能约为30kJ/mol。通过载体C分散在催化剂中的超小Ag纳米颗粒对所有反应物都有富集作用,使反应物在Ag纳米颗粒表面达到吸附饱和状态,从而加速偶联反应过程,并验证催化剂的反应动力学表明为零级反应。
The dehydrocoupling reaction between alcohols and hydrosilanes is considered to be one of the most atom-economical ways to produce Si-O coupling compounds because its byproduct is only hydrogen (H2), which make it extremely environmentally friendly. In past decades, various kinds of homogeneous catalysts for the dehydrocoupling of alcohols and hydrosilanes, such as transition metal complexes, alkaline earth metals, alkali metals, and noble metal complexes, have been reported for their good activity and selectivity. Nevertheless, the practical applications of these catalysts still remain unsatisfactory, which is mainly restricted by environmental impact and non-reusability. A facile and recyclable heterogeneous catalyst, ultra-small Ag nanoparticles supported on porous carbon (Ag/C) for the etherification of silanes, has been developed. It has high catalytic activity for the Si-O coupling reaction, and the apparent activation energy of the reaction is about 30 kJ/mol. The ultra-small Ag nanoparticles dispersed in the catalyst through the carrier C have an enrichment effect on all reactants, which makes the reactants reach the adsorption saturation state on the surface of Ag nanoparticles, thus accelerating the coupling reaction process and verifying that the kinetics of the reaction of the catalyst indicate a zero-grade reaction.