1 research outputs found
Hydrogenation of CO<sub>2</sub> to Dimethyl Ether over Brønsted Acidic PdZn Catalysts
Eschewing
the common trend toward use of catalysts composed of
Cu, it is reported that PdZn alloys are active for CO<sub>2</sub> hydrogenation
to oxygenates. It is shown that enhanced CO<sub>2</sub> conversion
is achievable through the introduction of Brønsted acid sites,
which promote dehydration of methanol to dimethyl ether. We report
that deposition of PdZn alloy nanoparticles onto the solid acid ZSM-5,
via chemical vapor impregnation affords catalysts for the direct hydrogenation
of CO<sub>2</sub> to DME. This catalyst shows dual functionality;
catalyzing both CO<sub>2</sub> hydrogenation to methanol and its dehydration
to dimethyl in a single catalyst bed, at temperatures of >270 °C.
A physically mixed bed comprising 5% Pd 15% Zn/TiO<sub>2</sub> and
H-ZSM-5 shows a comparably high performance, affording a dimethyl
ether synthesis rate of 546 mmol kg<sub>cat</sub><sup>–1</sup> h<sup>–1</sup> at a reaction temperature of 270 °C