Cerium-zirconium-aluminum-based composite material, cGPF catalyst and preparation method therefor

A method of preparing a cerium-zirconium-aluminum-based composite material, which comprises the following steps:

• (1) Dissolving pseudo-boehmite in citric acid aqueous solution, adjusting the pH value to 4-10 with ammonia water, filtering and drying after the reaction under stirring is completed to obtain a precipitate;
• roasting the precipitate at a temperature of 200-400° C. for 0.1-5 h to obtain a pre-treated material;
• wherein the mass ratio of pseudo-boehmite to citric acid is 5-20:1;
• (2) Adding the pre-treated material into a solution of mixed sol, adjusting the pH value to 4-10 with ammonia water after completely dissolution, filtering and drying after the reaction under stirring is completed to obtain a mixture precipitate;
• wherein the mixed sol is a sol containing cerium ions and zirconium ions;
• (3) Roasting the mixture precipitate at 500-600° C. for 1-10 h, and then at 800-1100° C. for 1-10 h to obtain the cerium-zirconium-aluminum composite material.