THE REDUCTION OF PLATINUM CONSUMPTION IN ENVIRONMENTAL CATALYSTS FOR COMPLETE OXIDATION OF VOLATILE ORGANIC COMPOUNDS

摘要

Pt/Co_3O_4/CeO_2-ZrO_2-SnO_2/□-Al_2O_3 catalysts were successfully prepared by both conventional co-precipitation and impregnation methods. The catalytic performances for toluene oxidation on these materials indicate that the addition of Co_3O_4 to the Pt/CeO_2-ZrO_2-SnO_2/□□-Al_2O_3 catalyst was significantly effective in reducing the platinum amount without further reduction in its activity. In fact, complete oxidation of toluene was realized by using the 1wt%Pt/11wt%Co_3O_4/16wt%Ce_(0.62)Zr_(0.20)Sn_(0.18)O_(2.0)/□□-Al_2O_3 catalyst at the temperature as low as 160 ℃, which was lower than that with the 5wt%Pt/□□-Al_2O_3 catalyst (170 ℃). Since the oxidation activities of both 1wt%Pt/16wt%Ce_(0.62)Zr_(0.20)Sn_(0.18)O_(2.0)/□□-Al_2O_3 and 1wt%Pt/11wt% Co_3O_4/□□-Al_2O_3 were below compared to that of the present 1wt%Pt/11wt%Co_3O_4/16wt%Ce_(0.62)Zr_(0.20)Sn_(0.18)O_(2.0)/□□-Al_2O_3, the main reason for the high toluene oxidation activity in the 1wt%Pt/11wt%Co_3O_4/16wt%Ce_(0.62)Zr_(0.20)Sn_(0.18)O_(2.0)□/□□-Al_2O_3 catalyst can be ascribed to the concerted effect of Pt, Co_3O_4, and Ce_(0.62)Zr_(0.20)Sn_(0.18)O_(2.0) on □-Al_2O_3.