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

Abstract

CuO/ZnO/Al2O3/MgO–Cr and -Mn catalysts are synthesized using nitrate route via co-precipitation 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 °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 °C to 450 °C crystallite size increases about 3 nm, and BET surface area decreases about 30 m2/g. The reduction characteristics of the catalysts are analyzed via TPR and H2-TGA, and H2 consumption values of Cr and Mn containing catalysts is found as 40% and 60%, respectively. Peak temperatures of Mn containing catalysts (290–325 °C) are lower than peak temperatures of Cr containing catalysts (300–360 °C) as confirmed by H2-TGA and H2-DTG. The optimum H2 consumption value of 52% is obtained with CuO/ZnO/Al2O3/MgO–Mn catalyst calcined at 350 °C.