Cu-promoted Pd/Al2O3 catalysts were prepared by selectively depositing Cu onto the Pd surface using a surface redox (SR) method, and their performance in the selective hydrogenation of acetylene was compared with that of Ag-promoted catalysts prepared by both the SR and the conventional impregnation method. The Cu-promoted catalysts prepared by SR showed higher ethylene selectivity and activity than Ag-promoted catalysts, particularly with small amounts of added promoter. The above results were obtained because Cu added by SR was deposited preferentially onto the low-coordination sites of Pd, which were detrimental to ethylene selectivity but took a small fraction of the Pd surface that was responsible for acetylene conversion, and also because Cu had an intrinsic activity for hydrogenation. The advantages of Cu-promoted catalysts prepared using Cu as a promoter and the SR process as the promoter-addition method were conclusively demonstrated in the present study.
Bibliographical noteFunding Information:
This work was supported by BASF Aktiengesellschaft, Germany, the Brain Korea 32 project, the Korea Science and Engineering Foundation (KOSEF) through the National Research Laboratory Program and the Human Resources Development of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 20104010100510 ).
- Acetylene hydrogenation
- Ethylene selectivity
- Surface redox method