Confined hot-pressurized water in Brønsted-acidic beta zeolite speeds up the O demethylation of guaiacol

IF 42.8 1区化学 Q1 CHEMISTRY, PHYSICAL Nature Catalysis Pub Date : 2025-01-09 DOI:10.1038/s41929-024-01282-6

Massimo Bocus, Elias Van Den Broeck, Xian Wu, Mathias Bal, Jeroen Bomon, Louis Vanduyfhuys, Bert F. Sels, Bert U. W. Maes, Veronique Van Speybroeck

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Abstract

Biorefinery technologies that convert lignin into platform chemicals are essential to reduce our future dependence on fossil resources. In these technologies, a key process is the acid-catalysed O demethylation of guaiacol derivatives in hot-pressurized water using Brønsted mineral acids or microporous zeolites. The fundamental understanding of how hydronium ions behave in a confined environment versus bulk is still limited. Here we investigate the O demethylation of guaiacol in hot-pressurized water with HCl or H-BEA zeolite catalysts to elucidate the impact of zeolite microporosity on reaction mechanisms and rates. Operando molecular simulations combined with experimental kinetic studies reveal that, regardless of the catalyst type, O demethylation follows a concerted O-activated S_N2 mechanism. The reaction rate is higher in the zeolite due to more active, under-coordinated hydronium ions. Additionally, the molecular organization of solvent and reactants around the confined active site plays a crucial role in modulating the association of the reacting species and the reaction kinetics.

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来源期刊

Nature Catalysis Chemical Engineering-Bioengineering

CiteScore

52.10

自引率

1.10%

发文量

140

期刊介绍： Nature Catalysis serves as a platform for researchers across chemistry and related fields, focusing on homogeneous catalysis, heterogeneous catalysis, and biocatalysts, encompassing both fundamental and applied studies. With a particular emphasis on advancing sustainable industries and processes, the journal provides comprehensive coverage of catalysis research, appealing to scientists, engineers, and researchers in academia and industry. Maintaining the high standards of the Nature brand, Nature Catalysis boasts a dedicated team of professional editors, rigorous peer-review processes, and swift publication times, ensuring editorial independence and quality. The journal publishes work spanning heterogeneous catalysis, homogeneous catalysis, and biocatalysis, covering areas such as catalytic synthesis, mechanisms, characterization, computational studies, nanoparticle catalysis, electrocatalysis, photocatalysis, environmental catalysis, asymmetric catalysis, and various forms of organocatalysis.