LaCuZnX (X=Al, Zr, Al+Zr) perovskite-like catalysts treated by NaBH₄ and their catalytic performance for CO₂ hydrogenation to methanol

La:Cu:Zn:X (X=Zr, Al, Al+Zr) perovskite-like catalysts were prepared by coprecipitation method followed by liquid phase reduction by NaBH₄. The physicochemical properties of the catalysts were tested by a series of characterization methods, and the catalysts were tested for methanol synthesis from CO₂ hydrogenation in a fixed-bed reactor. The results showed that the as-prepared catalysts were mainly composed of La₂CuO₄ perovskite-like crystal structure and doping of elements led to the spatial distortion of the perovskite-like structure. After reduction by NaBH₄, metal copper species and some high-valence copper species were found, which could be further reduced during the reaction. The CO₂ conversion was positively correlated with the Cu surface area, the dispersion of Cu, and the (Cu^α++Cu⁰)/Cu_total of the catalyst. The higher methanol selectivity was obtained when Cu^α+ binding energy was farther away from Cu⁺ binding energy. LCZA had the highest CO₂ conversion, LCZ catalyst possessed the highest methanol selectivity, and LCZZA catalyst presented the optimal methanol space time yield.