Pt-calcium cobaltate enables sorption-enhanced steam reforming of glycerol coupled with chemical-looping CH4 combustion

Sorption-enhanced steam reforming (SESR) process is usually highly energy intensive in producing high-purity hydrogen. Herein, the sorbent decarbonation was conducted in the presence of O-2 to enable the exothermic reaction between CaO and CoOx to form calcium cobaltate (CCO). By utilizing CCO as oxygen carrier (OC), the chemical-looping methane combustion was employed prior to the SESR of glycerol (SESRG), by which CCO was prereduced to Co catalysts and CaO sorbent, thereby significantly improving the H-2 yield from SESRG. With a Pt-doped CCO acting as precatalyst, CO2 sorbent, and OC, we realized 70% CH4 conversion and 96 vol% H-2 with 120% yield (based on glycerol) for 20 cycles, and the excess H-2 was due to steam gasification of coke. The promoting effects of Pt toward CH4 conversion and H-2 production were rationalized by CH4 temperature-programmed reduction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. Our results demonstrate the feasibility of process integration enabled by multifunctional materials.

Automated summary

The article introduces a method of process integration using multifunctional materials, significantly improving hydrogen production efficiency by pre-reducing CCO to catalysts and sorbents through a chemical method.