Pt/CexZr1-xO2 催化剂在含硫合成气中催化水煤气变换反应活性

 采用浸渍法制备了 Pt/Ce_xZr_1-xO₂ 催化剂, 通过 X 射线衍射和程序升温还原等方法对催化剂进行了表征, 并在固定床反应器中评价了催化剂在合成气和含硫合成气中的水煤气变换活性. 结果表明, 铈锆固溶体的氧化还原能力强于 CeO₂, Zr 的掺杂明显改善了 CeO₂ 的孔道结构, 其担载的 Pt 催化剂具有更高的金属分散度, 因而活性更高. 两种催化剂在含硫合成气中的催化活性较无硫合成气中的均有所降低, 且 H₂S 浓度越大, 催化剂活性下降越多, 但这种因吸附硫而引起的失活是可逆的, 即催化剂重新暴露在无 H₂S 重整气的还原性气氛下活性能基本恢复.

Water Gas Shift Activity of Pt/CexZr1-xO2 Catalysts in Sulfur-Containing Syngas

A series of Pt/Ce_xZr_1-xO₂ catalysts were prepared by the wet-impregnation method, characterized by X-ray diffraction and tem-perature-programmed reduction, and tested in the water gas shift (WGS) reaction. The results show that the Ce_xZr_1-xO₂ solid solution has higher redox ability, and doping ceria with zirconium apparently changes the pore structure. The Pt catalysts supported on Ce_xZr_1-xO₂ has higher Pt dispersion and WGS activity in pure reforming syngas. The WGS activity dropped in sulfur-containing syngas over the Pt/Ce_xZr_1-xO₂ catalysts. The loss of activity increases with the increase of H₂S content, but the deactivation of the catalyst due to H₂S adsorp-tion is reversible and can be readily reversed in the reducing atmosphere of the WGS mixture without H2S.