Ethanol Steam Reforming Catalyzed by Supported Rh Nanoparticles: Investigating the Effect of the Nature of the Oxides Supports

Rhodium, even presenting a great potential for many applications, remains little explored due to its very complicated stabilization in nanometric scale. However, its incorporation onto solid supports have shown as a promising alternative to overcome this limitation. We propose herein, the synthesis of Rh nanoparticles supported onto the surface of different commercial oxides (SiO2, ZnO, CeO2 and Al2O3) as catalyst with outstanding performances towards ethanol steam reforming aiming to systematically investigate the role played by the nature of the support towards the catalytic performances. The catalysts were obtained by a urea-assisted deposition method without any additional stabilizing or capping agent. Here, no modifications in the oxides structures and properties were observed after Rh incorporation, indicating the robustness of this strategy. The catalytic experiments (Figure 1), performed at 550 ºC and H2O/EtOH molar ratio = 3, showed an strong dependence between activity, selectivity, and stability and the nature of the oxide support probably due the differences in the intrinsic properties of each metal oxide such as the magnitude of the metal-support interactions and specific surface areas. Here, the best results in terms of ethanol conversion and selectivity for hydrogen production were observed with Rh/CeO2 catalyst, in agreement with their superior capability of oxygen storage and mobility at its surface, which is very attractive for applications towards gas-phase catalytic transformations with carbon-based compounds.