Preparation of CuCe_0.75Zr_0.25O_x composite by bacterial cellulose promoted sol-gel method and its catalytic performance in the toluene degradation at low temperature

Mesoporous CuCe_0.75Zr_0.25O_x composite was prepared by a simple sol-gel method with environmentally benign bacterial cellulose (BC) as a pore former and characterized by TG/DTG, N₂ adsorption-desorption, XRD, H₂-TPR, O₂-TPD and Raman; its catalytic activity in the degradation of toluene at low temperature was investigated in a fixed-reactor. The results indicated that BC with ultra fine three-dimensional networks and excellent compatibility is beneficial to the formation of gel with nitrate solution, to prepare the mesoporous catalyst. The catalyst performance of CuCe_0.75Zr_0.25O_x composite is significantly affected by the gel-form and gelling temperature during the preparation process. Over the ACCZ-70 catalyst prepared by alcohol gelling at 70 ℃, the temperature for a complete degradation of toluene (T₁₀₀) reaches 205 ℃, much lower than those reported in open literature; the excellent activity of ACCZ-70 is ascribed to its high reducibility at low temperature and high concentration of oxygen vacancies (0.81). In addition, adsorption phenomenon was observed in the range of 120-140 ℃ during the toluene degradation over WCCZ catalysts prepared by water gelling.