Sustainable hydrogen production by ethanol steam reforming using a partially reduced copper-nickel oxide catalyst.

Hydrogen production through the use of renewable raw materials and renewable energy is crucial for advancing its applications as an energy carrier. In this study, we fabricated a solid oxide solution of Cu and Ni within a confined pore space, followed by a partial reduction, to produce a highly efficient catalyst for ethanol steam reforming (ESR). At 300 °C, EtOH is completely converted, a H2 yield of approximately 5 mol per mol is achieved, and CO2 is the main carbon-containing product. This demonstrates that H2 production from bioethanol is an efficient and sustainable approach. Such a highly efficient ESR catalyst is attributed to the ability of the metal-oxide interface to facilitate the transformation of CHx adspecies from acetaldehyde decomposition into methoxy-like adspecies, which are reformed readily to produce H2 and consequently reduce CH4 formation.

Strong metal-support interactions between gold nanoparticles and ZnO nanorods in CO oxidation.

The catalytic performances of supported gold nanoparticles depend critically on the nature of support. Here, we report the first evidence of strong metal-support interactions (SMSI) between gold nanoparticles and ZnO nanorods based on results of structural and spectroscopic characterization. The catalyst shows encapsulation of gold nanoparticles by ZnO and the electron transfer between gold and the support. Detailed characterizations of the interaction between Au nanoparticles and ZnO were done with transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), electron paramagnetic resonance (EPR), and FTIR study of adsorbed CO. The significance of the SMSI effect is further investigated by probing the efficiency of CO oxidation over the Au/ZnO-nanorod. In contrast to the classical reductive SMSI in the TiO(2) supported group VIII metals which appears after high temperature reduction in H(2) with electron transfer from the support to metals, the oxidative SMSI in Au/ZnO-nanorod system gives oxygen-induced burial and electron transfer from gold to support. In CO oxidation, we found that the oxidative SMSI state is associated with positively charged gold nanoparticles with strong effect on its catalytic activity before and after encapsulation. The oxidative SMSI can be reversed by hydrogen treatment to induce AuZn alloy formation, de-encapsulation, and electron transfer from support to Au. Our discovery of the SMSI effects in Au/ZnO nanorods gives new understandings of the interaction between gold and support and provides new way to control the interaction between gold and the support as well as catalytic activity.