Comparison of hydrogen consumption behavior of chromium and manganese promoted copper-based catalysts

CuO/ZnO/Al2O3/MgO-Cr and -Mn catalysts are synthesized using nitrate route via coprecipitation method. The precursors are characterized by XRD. The decomposition behavior of the precursors is analyzed by Air-TGA. The catalysts calcined at 250, 300, 350 and 450 degrees C are characterized by XRD and BET. CuO particle size reduction and surface area of the catalysts are investigated. Increasing the calcination temperature from 350 degrees C to 450 degrees C crystallite size increases about 3 nm, and BET surface area decreases about 30 m(2)/g. The reduction characteristics of the catalysts are analyzed via TPR and H-2-TGA, and H-2 consumption values of Cr and Mn containing catalysts is found as 40% and 60%, respectively. Peak temperatures of Mn containing catalysts (290-325 degrees C) are lower than peak temperatures of Cr containing catalysts (300-360 degrees C) as confirmed by H-2-TGA and H-2-DTG. The optimum H-2 consumption value of 52% is obtained with CuO/ZnO/Al2O3/MgO-Mn catalyst calcined at 350 degrees C. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.