Synthesis and Characterization of Cu-Ni Bimetallic Catalysts Support on GO, rGO, and NGO

CO2 activation plays an important role in CO2 utilization. Thus, the catalyst consisting of Cu-Ni supported on graphene oxide (GO), ammonia modified graphene (NGO), and reduced graphene oxide (rGO) were synthesized. Their properties were analysed by BET, XPS, TEM, and TG-DSC. The specific surface area of supports followed the order of ammonia modified graphene (NGO) > graphene oxide (GO) > reduced graphene oxide (rGO). Cu-0 existed in rGO and NGO supported catalysts. 29.5% of Cu2+ was reduced to Cu+ or Cu-0 in rGO. In NGO, 30% of Cu2+ was reduced. Most of the Cu and Ni was dispersed uniformly on these two supports. In GO, some particles were sintered, which was composed of Cu and Ni with a size up to 100 nm. In rGO and NGO, the metal particle size was less than 50 nm. The CO2 activation energy was determined by TG-ESC experiment, and the calculation was done by Ozawa method. The results showed that CuNi-rGO and CuNi-NGO could activate CO2, and the activation energy (E) was 78.26 and 91.30 kJ.mol(-1), respectively. Compared with literature, these catalysts could reduce the activation energy (E) by 48%.