Synthesis of Low-Carbon Alcohols from Syngas over Cu–Fe/TiO ₂ Catalysts with an Anatase–Rutile Junction

The use of anatase–rutile mixed-phase TiO2 (P25) as a support improves both CO conversion and selectivity toward low-carbon alcohols (C1–C5 mixed alcohols) during syngas conversion over Cu–Fe bimetallic catalysts. A 61.4% selectivity to low-carbon alcohols was obtained at a CO conversion of 35.0%. The low-carbon alcohol yield (21.5%) over CuFe/P25 is 31 and 3 times higher than the yields over Cu–Fe catalysts supported on pure anatase TiO2 and pure rutile TiO2, respectively. The anatase–rutile synergy in P25 contributes to the high dispersion of Cu–Fe species and facilitates electron transfer from the P25 support to both Cu0 and FeCx active sites via metal–support interaction. CuFe/P25 enhances both the capabilities of CO adsorption, dissociation, and non-dissociative insertion and the formation of CHx, CHO, and HCOO intermediates. These findings suggest that tuning the crystalline phase of the support constitutes a rational strategy for enhancing the catalytic activity of the metal sites.