Abstract:
Selective hydrogenolysis of lignin-derived aryl ethers under mild temperature and pressure conditions is an
important milestone to be achieved to fulfill the future fuel demands from abundantly available biomass
resources. Selective hydrogenolysis requires precise modulation of surface active sites of the catalyst to
obtain the desired activity and selectivity. In this study, the selective hydrogenolysis of benzyl phenyl ether
to phenol and toluene is achieved in methanol and water medium at a very low temperature and low H2
pressure over a Pd nanoparticle decorated Ce-BTC metal–organic framework. The activity of the
developed catalyst is two times higher than that of Pd decorated CeO2. The structure–activity relationship
is established using catalytic measurements, X-ray photoelectron spectroscopy, and transmission electron
microscopy. The mechanistic insight into the hydrogenolysis of aryl ethers and the reasons behind the
superior activity of Pd/Ce-BTC to that of Pd/CeO2 are investigated using density functional theoretical
(DFT) calculations. Spectroscopic measurements and DFT calculations suggest that the higher Pd0/Pd2+
ratio and higher adsorption of benzyl phenyl ether over Pd/Ce-BTC and the higher adsorption of phenol
over Pd/CeO2 are factors responsible for the higher activity of Pd/Ce-BTC than that of Pd/CeO2. Efficient
recyclability and hot filtration tests reveal that the catalyst exhibits no noteworthy loss in the activity after
five consecutive cycles. The Pd/Ce-BTC catalyst displays a very high turnover frequency and low activation
energy, which are very attractive from the industrial perspective and academic point of view.
