Chitosan-lignin carbon framework-encapsulated Cu catalyst facilitates base-free hydrogen evolution from methanol/water

• Published in: Catalysis science & technology 2022-03, Vol.12 (6), p.1941-1949
• Main Authors: Pi, Yunhong, Wu, Xiuting, Zheng, Zefeng, Ma, Liang, Wang, Tiejun
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Carbon; Catalysts; Catalytic activity; Chitosan; Densification; Electrolytic cells; Encapsulation; Hydrogen; Hydrogen evolution; Hydrogen production; Lignin; Methanol; Noble metals; Proton exchange membrane fuel cells; Reforming; Selectivity; Self-assembly; Shift reaction; Stability; Storage capacity; Water gas; Zinc oxide
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/d1cy01698a

Methanol reforming in aqueous solution provides a significantly attractive and promising pathway to release hydrogen with mild H 2 release conditions and high H 2 storage capacity. Exploring non-noble metal-based catalysts with sufficiently high activity, stability, and selectivity for H 2 remains a great challenge. We report here the construction of a chitosan-lignin (CS-LN) carbon framework bio-composite-encapsulated Cu catalyst (Cu@CS-LN) with high loading and dispersion for base-free hydrogen generation from aqueous-phase methanol reforming below 210 °C. With optimized conditions, the hydrogen generation rate of Cu@CS-LN (2.5 × 10 5 μmol H 2 g Cu −1 h −1 ) represents an approximately 2-fold enhancement compared with Cu@CS without lignin incorporation, and more than 3-5 times higher than commercial Cu-based catalysts such as Rainie Cu or CuO/ZnO. The catalyst underwent an intensified water gas shift reaction (WGSR), and it also exhibited extraordinary selectivity toward the CO byproduct. The unique carbon framework structure of CS-LN through electrostatic densification self-assembly not only enhanced the adsorption and dispersion of Cu species, but it also stabilized and further reduced the Cu particles to active phase Cu during the hydrogen generation reaction to promote catalytic activity and stability without obvious catalyst deactivation detected after running for 150 hours. This specific hydrogen production technology exhibits great potential for hydrogen-powered polymer electrolyte membrane (PEMFCs) fuel cells. A bio-composite Cu catalyst encapsulated and highly dispersed in a chitosan-lignan carbon framework efficiently facilitates base-free hydrogen evolution from a methanol/water reforming reaction.