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A series of B-site Co3+-doped LaCu x Co 1-x O 3 (x = 1, 0.8, 0.6, 0.4, 0.2) perovskites were synthesized by solution combustion method and their physicochemical properties were comprehensively characterized. The perovskite-coated Cu foams were applied as monolithic catalysts for methanol steam reforming to produce H 2. Results showed that an appropriate amount of Co3+ doping led to the stabilization of crystal structure, the reduction of particle size, the improvement of chemical constitution, the enhancement of reduction behavior, the decrease of acidity, the increase of specific surface area, and the optimization of surface chemical state. The monolithic catalyst loaded with LaCu 0.4 Co 0.6 O 3 showed the highest methanol conversion rate and H 2 production rate, the lowest CO selectivity, the best stability and the lowest carbon deposition. However, excess Co3+ resulted in a degradation of the catalytic performance. The findings of this work suggested that introducing Co3+ might be a promising way to enhance the activity of Cu species for obtaining a better Cu-containing perovskite-based monolithic catalyst. [Display omitted] • Co3+-doped LaCuO 3 perovskites are prepared and used for methanol steam reforming. • The Co3+ doping significantly affects the physicochemical properties of perovskite. • LaCu 0.4 Co 0.6 O 3 exhibits the best performance due to its excellent characteristics. • Co3+ can effectively optimize the active center and enhance the activity of Cu0. [ABSTRACT FROM AUTHOR]

Co-precipitation method was applied to prepare five Cu-containing spinels CuB 2 O 4 with different B-sites (CuCo 2 O 4 , CuAl 2 O 4 , CuMn 2 O 4 , CuLa 2 O 4 , CuCr 2 O 4) and the physicochemical properties of the spinels were characterized comprehensively. The Cu-containing spinels were then washcoated on Cu foams to fabricate monolithic catalysts and the catalytic performance of the catalysts under different reaction conditions was investigated in a methanol steam reforming microreactor. The effects of B-site on the structure-activity relationship and sustained release catalysis were discussed in detail. Results showed that the CuCo 2 O 4 spinel with small particles, excellent reducibility, low acidity, large specific surface area and superior surface chemical state led to the best performance of the monolithic catalyst loaded with CuCo 2 O 4. The B-site resulted in completely different characteristics of spinels, leading to diverse sustained release properties during the catalysis. Owing to the sustained release behavior, the catalytic stability of the Cu-containing spinel was significantly improved compared with the conventional Cu-based catalyst. • Cu-containing spinels with different B-sites were used for methanol steam reforming. • CuCo 2 O 4 spinel exhibited the best performance due to its excellent characteristics. • The effects of B-site on the structure-activity relationship were discussed. • The process of the sustained release catalysis was proposed. [ABSTRACT FROM AUTHOR]

Hydrogen generation via methanol steam reforming is a promising method for producing renewable energy. In this work, a series of Mn2+-substituted CuAl 2 O 4 spinels were prepared by solution combustion method, and the crystal structure, micromorphology, chemical constitution, reduction behavior, acidity, specific surface area and surface chemical state of the spinels were comprehensively characterized by various equipments. The obtained spinels were washcoated on Cu foams to prepare monolithic catalysts, and the catalytic performance of the catalysts was evaluated in a methanol steam reforming microreactor. Compared with the binary Cu–Al spinel, the Mn2+ substitution led to a decrease in the particle size, a change in the chemical composition and reduction behavior, a decline in the acidity, an increase in the specific surface area, and an improvement in the surface chemical state. As a result, the release rate of active Cu from the Mn-containing CuAl 2 O 4 spinel was significantly slowed down and the formed nanoparticles were fine, which was believed to be in favor of maintaining a stable catalytic performance longer. Among the prepared catalysts, the monolithic catalyst loaded with Cu 0.4 Mn 0.6 Al 2 O 4 exhibited the highest activity and stability. The findings of this work suggested that introducing Mn2+ might be a promising way to regulate the Cu releasing property for obtaining a better sustained release catalyst system. [Display omitted] [ABSTRACT FROM AUTHOR]