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Porous LaFeO3 Prepared by an in Situ Carbon Templating Method for Catalytic Transfer Hydrogenation Reactions
journal contribution
posted on 2019-04-05, 00:00 authored by Ping Xiao, Junjiang Zhu, Dan Zhao, Zhen Zhao, Francisco Zaera, Yujun ZhuCatalytic
transfer hydrogenation is an attractive route for the synthesis of
biomass-derived chemicals. However, development of efficient, low-cost,
and stable catalysts for that reaction is still a challenge. Here,
we report on the preparation and testing of a non-noble perovskite
oxide (LaFeO3) catalyst synthesized by an in situ carbon
templating method. We show that our catalyst is quite active and selective
toward the hydrogenation of unsaturated organics. Compared to an analogous
LaFeO3 catalyst prepared by a more traditional method,
using citric acid, the new LaFeO3 exhibited a more porous
structure, a La-enriched surface composition, and abundant oxygen
vacancies, all characteristics that improve contact with the reactants.
In the case of the conversion of furfural to furfuryl alcohol (FOL)
using iso-propanol as hydrogen donor, the new LaFeO3 showed
a furfural conversion of 90% and a selectivity to FOL of 94%, significantly
higher than with the reference LaFeO3 prepared by the traditional
sol–gel method (60 and 91%, respectively). Moreover, our new
LaFeO3 catalyst can be recovered after a calcination treatment,
with no appreciable changes in its structure or activity, a test that
we repeated six times, and can promote the hydrogenation of other
carbonyl compounds containing electron-withdrawing groups. A reaction
mechanism is proposed in which metal cations are the adsorption sites
for iso-propanol and oxygen vacancies are the adsorption sites for
furfural, and where the conversion proceeds following an acid–base
mechanism. We believe that the novel use of perovskites as catalysts
for hydrogenation reactions reported here may be easily extendable
to other processes, and that our carbon-templating synthetic approach
offers a way to synthesize viable perovskite catalysts with high surface
areas for optimized activity.