中文摘要：

考察了 In/SO42–/TiO2 （In/STi）催化剂上甲烷选择性催化还原（CH4-SCR）NOx 的活性, 分析了硫酸化对催化活性的促进作用. 结果表明, 硫酸化影响了 In 在催化剂表面的存在形态和 CH4 的活化产物, 从而提高了催化剂活性. 吡啶红外光谱分析表明, 硫酸化后的 STi 载体可提供足够强度的 B 酸位, 有利于活性中心 InO＋物种的形成. 原位红外光谱分析表明, In/TiO2 催化剂上 CH4 的活化产物为完全氧化的 CO2 和 H2O, 而硫酸化后的 In/STi 催化剂上 CH4 的活化产物为 HCOO–, 该物种被认为是 CH4-SCR 反应的重要中间体, 它的生成为 In/STi 催化剂上 CH4-SCR 反应的速控步骤.

英文摘要：

The catalytic performance and the promotional mechanism of sulfation for selective catalytic reduction of NO by CH4 over sulfated titanium-loaded In （In/STi） were investigated. An enhancement of catalytic activity was obtained over the In/STi catalysts. Sulfation influenced the existent state of surface indium species and determined the activation species of CH4. Py-IR analysis showed that the sulfated In/STi catalyst had strong Brφnsted acid sites, which were beneficial to the formation of active InO^＋ species. DRIFTS studies further revealed the distinguish reaction intermediates of CH4-SCR of NO over the sulfated and unsulfated catalysts. On the In/TiO2 and TiO2 catalysts, the activation species of CH4 was the fully oxidized products of CO2 and H20, while on the STi and In/STi catalysts, HCOO-, the real reductant for CH4-SCR of NO, was detected as the main intermediate species. In addition, the formation of HCOO^- was the rate-determining step in CH4-SCR of NO on the In/STi catalyst.