Cu/REO (RE = La, Pr, Sm, Y, Ce) catalysts for methanol steam reforming: Understanding the interaction between Cu and individual REO supports
Xiaofei Liu, Jiamei Ma, Lei Mao, Junwei Xu, Xianglan Xu, Xiuzhong Fang, Xiang Wang
Abstract
With the objective to develop applicable catalysts for methanol steam reforming (MSR) to generate H 2 , five individual REOs were prepared as supports for Cu/CuO to understand the Cu/CuO-support interaction. Pure REO supports with a cubic phase are successfully fabricated except that monoclinic La 2 O 2 CO 3 carbonate is formed for La 2 O 3 sample, which has negative effect on the reaction. The reaction performance ranks as 5 % Cu/CeO 2 > 5 % Cu/Sm 2 O 3 > 5 % Cu/Pr 6 O 11 > 5 % Cu/Y 2 O 3 > 5 % Cu/La 2 O 3 for the samples. It has been disclosed that the quantities of surface basic sites, active O 2 – species, Cu + contents/percentage and active Cu surface area are positively correlated to the reaction performance. Thus, the interaction together of these four factors decides the reaction performance. In addition, In-situ DRIFTS results of CH 3 OH adsorbing/steam reforming have demonstrated that on the optimal 5 % Cu/CeO 2 , the reactive monodentate m-HCOO* intermediate is formed, which is absent on 5 % Cu/Y 2 O 3 with worse performance.