Synthesis of methanol over highly dispersed Cu-Fe based catalysts derived from layered double hydroxides.

In this paper, catalysts with different aluminum contents were prepared by a co-precipitation method using LDHs (layered double hydroxides) as the precursors through the adjustment of Cu 2+  : Fe 2+ , and the catalysts were named LDO catalysts. The effect of aluminum on CO 2 hydrogenation to methanol was investigated by evaluating the characterization. With the addition of Al, Ar physisorption results showed an increase in BET-specific surface area, TEM demonstrated a decrease in catalyst particle diameter, XRD showed that Cu and Fe existed in the catalyst mainly in the form of CuFe 2 O 4 and CuO, XPS demonstrated a decrease in electron cloud density and an increase in base sites and oxygen vacancies, and CO 2 -TPD and H 2 -TPD results indicated that Al promoted the dissociation and adsorption of CO 2 and H 2 . When the reaction temperature was 230 °C, the pressure was 4 MPa, H 2 /CO 2 = 2.5 and the space velocity was 2000 ml (h g cat ) -1 , the best conversion (14.87%) and the highest methanol selectivity (39.53%) of the catalyst were obtained at 30% aluminum content.