Boosting selective hydrogenation through hydrogen spillover on
supported-metal catalysts at room temperature
Abstract
Highly efficient hydrogenation of unsaturated substrates with strong
absorption on metals at low temperatures is a long-term pursuit.
However, due to the scaling relationship of high binding energies on
metals, the poor activity and/or selectivity are frequently observed.
Herein, we described a strategy of hydrogen spillover to break this
scaling relationship to enable highly performed hydrogenation at low
temperatures by constructing the dual-active site in supported-metal
catalysts. Hydrogen and reactants are selectively activated on metal and
the second active sites on support, respectively. Hydrogenation
sequentially occurs on the second active sites via hydrogen spillover
from metal to support. Easy desorption of surface-bounded products
substantially re-generates the active sites. Guided by this design, for
cinnamaldehyde hydrogenation, PtCo alloys (for H2 dissociation)
supported on hydroxyl-abundant CoBOx (for aldehyde activation) delivered
a high turnover frequency of 2479 h-1 (two orders of magnitude over
PtCo/C) and 94.5% selectivity of cinnamyl alcohol at room temperature.