Reaction Mechanism And Kinetics Study Of Carbon Monoxide Self-sustained Combustion On The CuCe_0.75Zr_0.25O_y Catalyst

Recently,steel enterprises are one of great importance for national energy-saving and emission-reduction.Direct combustion emissions of converter off-gas?CO?35%?O2?2% and CO2?40%?in steelmaking process creats energy waste and environment pollution.In order to solve these problems,self-sustained catalytic combustion method is proposed to realize CO conversion efficiently with low temperature.The reaction mechanisms and stability combustion of CO self-sustaining combustion were studied by theoretical analysis and experiment research over catalysts.Cu Ce0.75Zr0.25 Oy,CuCe_0.75Zr_0.25O_y?H?and Ce0.75Zr0.25 Oy catalysts were obtained to study reaction mechanism,using various characterization methods and in situ DRIFT,and verified by kinetic experiments.The results show that catalytic activity decreases as CuCe_0.75Zr_0.25O_y> CuCe_0.75Zr_0.25O_y?H?> Ce0.75Zr0.25 Oy,corresponding the relative reation rates r=6.02×10-7×PCO0.68PO20.03,r=5.86×10-7×PCO0.8PO20.07 and r=5.7×10-7×PCO0.75PO20.12,respectively.Reaction sensitivity follows the order dispersed Cu Ox > Cu-Ce-Zr-Oy solid solution > Ce-Zr-Oy solid solution.M-K mechanism was the crucial reaction pathway on Cu Ce0.75Zr0.25 Oy,and L-H mechanism mainly occurred on CuCe_0.75Zr_0.25O_y?H?and Ce0.75Zr0.25 Oy catalysts.CO self-sustaining combustion and stability tests on Cu Ce0.75Zr0.25 Oy indicated that self-sustaining combustion realized with 3%CO+3%O2/N2,and remain high thermal stability for 100 h under the reaction gas?10 %CO?.CO critical concentration of selfsustaining combustion decreased as Ce0.75Zr0.25Oy?9.21%¹3.32%?> CuCe_0.75Zr_0.25O_y?H??3.99%⁵.16%?> CuCe_0.75Zr_0.25O_y?2.49%³.66%?.It showed that the research results expand understanding about microscopic reaction mechanism of CO combustion,and realize reaction kinetics stage?CO<3%?to self-sustained combustion stage?CO?3%?.