Enhancing the Dispersion of Cu-Ni Metals on the Graphene Aerogel Support for Use as a Catalyst in the Direct Synthesis of Dimethyl Carbonate from Carbon Dioxide and Methanol
Varisara Deerattrakul, Apichaya Panitprasert, Pralachoak Puengampholsrisook, Paisan Kongkachuichay
Abstract
Graphene has attracted attention because of its interesting properties in catalyst applications including as a catalyst support; however, it is known that the graphene can be restacked, forming a graphite-like structure that leads to poor specific surface area. Hence, the high-porosity graphene aerogel was used as a Cu-Ni catalyst support to produce dimethyl carbonate (DMC) from carbon dioxide and methanol. In this work, we have introduced a new synthesis route, which can improve the dispersion of metal particles on the graphene aerogel support. Cu-Ni/graphene aerogel catalysts were synthesized by a two-step procedure: forming Cu-Ni/graphene aerogel catalysts via hydrothermal reduction and then Cu-Ni loading by incipient wetness impregnation. It is found that the catalyst prepared by the two-step procedure exhibits higher DMC yield (25%) and MeOH conversion (18.5%) than those of Cu-Ni loading only by an incipient wetness impregnation method. The results prove that this new synthesis route can improve the performance of Cu-Ni/graphene aerogel catalysts for DMC production.