Enhanced CO2 hydrogenation reaction by Tuning interfacial Cu/ZnOx through synergistic interactions in the precursors

Abstract

The Cu/ZnO/Al₂O₃ is a typical industrial catalyst for water–gas-shift reaction and methanol synthesis, and is also gaining momentum in CO₂ hydrogenation reaction. The dynamic evolution of the phases and microstructures of the precursor of this catalyst leads to a notable synergistic effect that defines its overall catalytic function and performance. To gain insights into the role and interaction between the relevant precursors, we compared Cu/ZnO/Al₂O₃ catalysts using a conventional co-precipitation and a fractional precipitation method, where the latter one shows an enhanced Cu/ZnO_x interface due to a thorough and strong interaction between two components in the precursor. The ZnO_x decoration on Cu with unsaturated Zn^δ+ species boosted the methanol formation to a rate of 508 g_CH3OH‧kg_cat⁻¹‧h⁻¹ with 58 % selectivity at 513 K and 3 MPa. This work provides mechanistic insights into the synergistic interplay between the involved phases in the Cu/ZnO/Al₂O₃ catalyst.