Preparation of NiO/MgAl2O4 catalysts by ball-milling method for catalytic lean burn of high-diluted methane

NiO catalysts supported on MgAl2O4 spinel were prepared by ball-milling method, and the effects of nickel source, NiO loading, ball-to-powder ratio, ball-milling speed, and calcination temperature on the catalytic lean burn of high-diluted methane were investigated. The catalysts were characterized by H2-TPR, BET, XRD and SEM, etc. The results showed that weaker interaction between nickel precursor and carrier was found in catalysts prepared by ball-milling method than that by impregnation method or deposition-precipitation method, to produce NiO species with higher catalytic activity after calcination. In ball milling method, all factors of nickel source, NiO loading, ball-to-powder ratio, ball-milling speed and calcination temperature affected catalytic performances of the catalyst by altering the grain size or bonding state of NiO species on carrier surface. The prepared NiO/MgAl2O4 catalyst demonstrated better stability and activity under the conditions of nickel acetate as nickel source, NiO mass fraction of 10%, ball-to-powder ratio of 2:1, ball-milling speed of 400 r/min, and calcined temperature of 700℃. Its pseudo first-order reaction rate constant at 600℃ was 0.489 L/(g•s), higher than that of La0.8Ca0.2FeO3 or La0.8Sr0.2MnO3 perovskite supported on MgAl2O4 spinel. © 2020, Editorial Office of FINE CHEMICALS. All right reserved.