부산대학교 도서관

In this paper, a fixed-bed reactor is used to study the influence of different conditions on carboncatalyzed CO2–CH4 reforming. The surface structure and functional groups of carbonaceous materialhave been characterized through SEM, XPS, XRD, BET and chemical titration before and after the reaction. Studies have revealed that under non-catalytic condition, methane pyrolysis happens first, followed bythe gasification reaction between CO2 and carbon deposit produced from the pyrolysis. While withcarbonaceous material, CO2 gasification, methane pyrolysis and CO2–CH4 reforming can take place at thesame time, with the reforming as the main reaction, CO2 gasification and methane pyrolysis as the sidereaction. Catalytic activity varies from one carbonaceous material to another, but their reaction trend isthe same on the whole. Those high specific surface area carbonaceous materials show higher catalyticactivity. The increase in reaction temperature and residence time of the reforming can improve theconversion of reactant gas. Adjusting the partial pressure of methane can control carbon–hydrogen ratio ofthe synthesis gas. XPS and XRDcharacterizationsdemonstrate that the structural ordering of carbonaceousmaterials becomes a little messier after the reforming reaction, and the number and content of oxygenfunctional groups decrease. That means these oxygen functional groups on the surface of carbonaceousmaterials are involved in the reforming and these groups along with pore structure on the surface are themajor factors influencing the catalytic properties. Different oxygen species make the nature of electricalenergy on the surface different; the catalytic activity depends on the polarity of oxygen from differentspecies. Those whose polarity is strong have strong activity. The dipole force can be associated withmethane in the form of hydrogen bond, so that the material can display strong activity. Those whosepolarity is weak have weak activity, the catalytic activity is weak too. The results of chemical titration andXPS characterization show that the oxygen in the anhydride and lactone structures on the surface ofcarbonaceous materials are active oxygen, and which is the main active component, it can reduce theactivation energy of methane dehydrogenation.