PdCu supported on dendritic mesoporous CexZr1-xO2 as superior catalysts
to boost CO2 hydrogenation to methanol
Abstract
A dendritic PdCu/Ce0.3Zr0.7O2 (PdCu/CZ-3) catalyst was prepared for
boosting the catalytic performance of CO2 hydrogenation to methanol
(MeOH). The open dendritic pore channels and small particle sizes
increase the accessibility between the active sites (PdCu alloy and
oxygen vacancy) and the reactants (H2 and CO2). More spillover hydrogen
could be generated due to the highly dispersed PdCu active metals over
the PdCu/CZ-3 catalyst. PdCu/CZ-3 can stimulate the generation of more
Ce3+ cations, which is beneficial to produce more oxygen vacancies on
the surface of the CZ-3 composite. Spillover hydrogen and oxygen vacancy
could promote the formate and methoxy routes over PdCu/CZ-3, which were
the primary intermediates to produce MeOH. PdCu/CZ-3 displayed the
highest CO2 conversions (25.5 %), highest MeOH yield (6.4 %), highest
PdCu- TOFMeOH (7.7 h-1) and superior 100 h long-term stability than
those of other PdCu/CexZr1-xO2 analogs and the reference PdCu/CeO2 and
PdCu/ZrO2 catalysts.