The Promotional Effects of ZrO2 and Au on the CuZnO Catalyst Regarding the Durability and Activity of the Partial Oxidation of Methanol

Abstract

Abstract:The promoter ZrO 2 was applied to prevent Cu crystallites from sintering over CZ (ca. Cu 30 wt.% and Zn 70 wt.%) under partial oxidation of the methanol (POM) reaction. Gold was selected to promote the performance of CZrZ (ca. Cu 31 wt.%, Zr 16 wt.%, and Zn 53 wt.%) catalyst to overcome a high ignition temperature of 175 • C and CO selectivity (S CO ) (>10% at T. > 200 • C). Experimentally, the deactivation rate constant of A 5 CZrZ (ca. Au 5 wt.%, Cu 31 wt.%, Zr 17 wt.%, and Zn 47 wt.%) and CZrZ was 1.7 times better than A 5 CZ (ca. Au 5 wt.%, Cu 31 wt.%, and Zn 64 wt.%) and CZ. The methanol conversion of CZrZ and A 5 CZrZ catalysts was kept higher than 70% for 12 h in an accelerated aging process. Meanwhile, the Au prompted more methoxy species oxidizing to formate on Cu + -rich A 5 CZrZ surface at lower temperature, and also improved CO transfer from formate reacting with moveable oxygen to form CO 2 . The S CO can lower to ca. 6% at 200 • C after adding 3-5% of gold promoter. These features all prove that the CZ catalyst with ZrO 2 and Au promoters could enhance catalytic activity, lower the S CO and ignition temperature, and maintain good durability in the POM reaction.

Advances in Enhancing the Stability of Cu-Based Catalysts for Methanol Reforming

“…Some researchers have also worked to prevent catalyst sintering. The addition of ZrO 2 to Cu/ZnO by Huang et al improved catalyst durability [95]. Different promoters have different effects on the same catalyst.…”