Pt-Calcium-Cobaltate Enables Sorption-Enhanced Steam Reforming of
Glycerol Coupled with Chemical Looping CH4 Combustion
Abstract
As an efficient approach to high-purity hydrogen, the sorption-enhanced
steam reforming (SESR) is usually highly energy-intensive. Herein, the
sorbent decarbonation was conducted in the presence of O2 to enable the
exothermic reaction between CaO and cobalt oxides to form calcium
cobaltate (CCO). By utilizing CCO as oxygen carrier (OC), the chemical
looping methane combustion (CLMC) was employed prior to the SESR of
glycerol (SESRG). The CCO was pre-reduced to generate a multi-functional
material composed of metallic Co catalysts and CaO sorbent, which can
significantly improve the H2 yield from SESRG. With a simple Pt-doped
CCO acting as pre-catalyst, CO2 sorbent and OC, we realized 70% CH4
conversion and 96 vol.% H2 with 120% yield for 20 cycles. The
promoting effects of Pt towards CH4 conversion and H2 production were
rationalized by CH4-TPR, XPS, SEM and TEM. Our results demonstrate the
feasibility of process integration and intensification enabled by
multi-functional materials.