论文部分内容阅读
采用脉冲反应和程序升温氧化反应考察了Ni/MgAl2 O4 和La2 O3 Ni/MgAl2 O4 催化剂上CO歧化和甲烷催化分解的程度。结果表明 ,在相同处理条件下 ,Ni/MgAl2 O4 催化剂上CO的歧化程度远高于La2 O3 Ni/MgAl2 O4 催化剂 ,Ni/MgAl2 O4 催化剂上甲烷分解产生的积炭量是La2 O3 Ni/MgAl2 O4 催化剂上的 4.2 8倍。利用甲烷处理La2 O3 Ni/MgAl2 O4 催化剂后 ,其X光电子能谱 (XPS)的C1s谱中NixC的结合能比Ni/MgAl2 O4 催化剂高。这证实了催化剂中较高正价态镧的存在 ,使得还原态催化剂的金属镍表面电子向镧上迁移 ;还原态金属粒子电子浓度降低 ,使得催化剂上CO歧化和甲烷分解反应的速率降低 ,从而使催化剂表现出较强的抗积炭能力
The extent of CO disproportionation and methane catalytic decomposition on Ni / MgAl 2 O 4 and La 2 O 3 Ni / MgAl 2 O 4 catalysts was investigated by pulse reaction and temperature programmed oxidation. The results show that under the same treatment conditions, the degree of disproportionation of CO on Ni / MgAl 2 O 4 catalyst is much higher than that of La 2 O 3 Ni / MgAl 2 O 4 catalyst. The amount of coke deposited on Ni / MgAl 2 O 4 catalyst is La 2 O 3 Ni / MgAl 2 O 4 4.2 8 times on the catalyst. After treating La2 O3 Ni / MgAl2 O4 with methane, the binding energy of NixC in the C1s spectrum of XPS was higher than that of Ni / MgAl2 O4. This confirms the existence of the higher valence state lanthanum in the catalyst so that the electrons on the surface of the nickel catalyst of the reduced catalyst migrate to the lanthanum and the electron concentration of the reduced metal particles decreases so that the rate of CO disproportionation and methane decomposition reaction on the catalyst is reduced, The catalyst showed strong resistance to carbon deposition capacity