DFT studies on H2O adsorption and its effect on CO oxidation over spinel Co3O4 (110) surface

Structural Origin: Water Deactivates Metal Oxides to CO Oxidation and Promotes Low‐Temperature CO Oxidation with Metals

“…Interestingly, it can play completely different roles in the presence of either metals or metal oxides, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] which are the two most common types of the catalysts. Interestingly, it can play completely different roles in the presence of either metals or metal oxides, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] which are the two most common types of the catalysts.…”

“…The following suggestions regarding the water poisoning effect have been proposed: [7][8][9][10][11][12] 1) water molecules strongly adsorb at the active site, thus blocking the CO adsorption; or 2) water dissociation occurs on the catalyst surface to form a surface OH group that inhibits the adsorption of CO or O 2 ; or 3) the formation of graphitetype carbon deposits or surface carbonate (CO 3 2À ) species. The following suggestions regarding the water poisoning effect have been proposed: [7][8][9][10][11][12] 1) water molecules strongly adsorb at the active site, thus blocking the CO adsorption; or 2) water dissociation occurs on the catalyst surface to form a surface OH group that inhibits the adsorption of CO or O 2 ; or 3) the formation of graphitetype carbon deposits or surface carbonate (CO 3 2À ) species.…”

“…Interestingly, it can play completely different roles in the presence of either metals or metal oxides, [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] which are the two most common types of the catalysts. [7][8][9][10][11][12][13][14][15] Specifically, morphology-controlled Co 3 O 4 [7,16,17] displays extraordinarily high catalytic activity for CO oxidation at very low temperatures (ca. [1][2][3][4][5][6] On the other hand, it can be a devastatingly poisonous species on the surface of metal oxides, the best example being the waterinduced deactivation on tricobalt tetraoxide (Co 3 O 4 ).…”

“…On one hand, a moderate amount of water on the surface of late-transition metals such as Au, Pt, and Pd, can promote low-temperature CO oxidation, which is one of the hottest topics in catalysis because of the environmental concerns. [7][8][9][10][11][12] It is worth emphasizing that transition-metal oxides have received an increasing amount of attention for CO oxidation because of their unexpectedly high catalytic activities, low price, and especially the rich surface chemistry which affords the potential to tune the catalytic properties to a considerable degree. [7][8][9][10][11][12][13][14][15] Specifically, morphology-controlled Co 3 O 4 [7,16,17] displays extraordinarily high catalytic activity for CO oxidation at very low temperatures (ca.…”

“…However, in the presence of trace amounts of water its activity is dramatically reduced. [7][8][9][10][11][12] It is worth emphasizing that transition-metal oxides have received an increasing amount of attention for CO oxidation because of their unexpectedly high catalytic activities, low price, and especially the rich surface chemistry which affords the potential to tune the catalytic properties to a considerable degree. [18][19][20] Moreover, the poisoning effect of H 2 O has also been reported for other oxide-based catalysts such as CuO and MnO x , and it may well be a common issue in many oxide systems.…”