Bimetallic catalysts for hydrogen generation

Abstract

Research interest in bimetallic catalysts is mainly due to their tunable chemical/physical properties by a number of parameters like composition and morphostructure. In catalysis, numerous bimetallic catalysts have been shown to exhibit unique properties which are distinct from those of their monometallic counterparts. To meet the growing energy demand while mitigating the environmental concerns, numerous endeavors have been made to seek green and sustainable energy resources, among which hydrogen has been identified as the most promising one with bimetallic catalysts playing important roles. This tutorial review intends to summarize recent progress in bimetallic catalysts for hydrogen production, specifically focusing on that of reforming technologies as well as the relevant processes like water-gas shift (WGS) and CO preferential oxidation (PROX), and emphasizing on the fundamental understanding of the nature of catalytic sites responsible for generating high purity hydrogen and minimizing carbon monoxide formation. Meanwhile, some important synthesis and characterization methods of bimetallic catalysts developed so far are also summarized.

Bi-component Cu2O–CuCl composites with tunable oxygen vacancies and enhanced photocatalytic properties

“…Distinctly, the optical absorptions of the Cu 2 O-CuCl samples are stronger than that of the Cu 2 O sample at the visible light region. Such phenomenon should be assigned to the existence of oxygen vacancies [16,17], indicating that the Cu 2 O-CuCl samples are more effective visible light response material. However, the increase for the optical absorption intensity is not always going on with the rise of the Cl/O molar ratio, suggesting that the optimum synergistic effect between Cu 2 O and CuCl should exist for the optical absorption.…”

“…More importantly, recent studies indicate that the presence of oxygen vacancies can effectively improve the photoabsorption and reduce the chance of charge recombination, ultimately resulting in an enhanced photocatalytic performance [16,17]. Thus, much effort has been devoted to construct the oxygen vacancies.…”

The Applications of Morphology Controlled ZnO in Catalysis

“…Methanol steam reforming (MSR) has been extensively studied for hydrogen production [104][105][106][107], primarily because of low sulfur content, low carbon/hydrogen ratio, and the relatively low reforming temperature • C) of methanol. In order to achieve a compact and highly efficient fuel cell system, a MSR catalyst with high activity and selectivity is essential [108].…”

Methanol dissociation on bimetallic surfaces: validity of the general Brønsted–Evans–Polanyi relationship for O–H bond cleavage

“…12 In fact, bimetallic PdZn based catalysts were found to have an activity similar to that of copper based catalysts 13 for methanol reforming, but being more thermally stable and also presenting a higher hydrogen selectivity.…”