methane;
nickel;
partial oxidation;
methane conversion;
syngas;
temperature programmed measurements;
D O I:
10.1016/S0920-5861(98)00336-8
中图分类号:
O69 [应用化学];
学科分类号:
081704 ;
摘要:
The oxidative chemistry of methane over nickel catalysts dispersed on silica, alumina, titania, ceria and zirconia supports has been studied. Temperature programmed reduction (TPR) has been used to study the reduction characteristics of the catalysts. These measurements reveal the presence of two distinct types of nickel oxide, which are reduced at significantly different temperatures on the different catalysts. The activity for methane conversion and selectivity towards partial oxidation has been studied as a function of reaction temperature using temperature programmed reaction spectroscopy (TPRS). Ni/SiO(2) showed the highest activity and selectivity towards CO formation. At 1160 K the selectivity towards CO formation varied from 85% for Ni/SiO(2) down to 29% for Ni/Al(2)O(3). In addition, the transient activity of a partially reduced Ni/CeO(2) catalyst and nonreduced Ni/SiO(2) and Ni/TiO(2) catalysts have been studied. The temperature at which methane activation occurs on the different catalysts has also been examined. (C) 1998 Elsevier Science B.V. All rights reserved.