image: Schematic diagram of the preparation of Pd/CNFM
Credit: H.-P. Zhao et al.
Nitrogen-doped carbon (CN) materials unique ability to adsorb phenol in a non-coplanar configuration, coupled with the weak interaction between the generated cyclohexanone and the support, effectively inhibits over-hydrogenation. This characteristic allows CN-supported catalysts to achieve high selectivity towards cyclohexanone, making them extensively investigated in the field of phenol hydrogenation. CN particulate catalysts are commonly employed in phenol hydrogenation, yet their separation from the final products poses a significant challenge. Even with separation processes in place, trace amounts of catalyst (ppm or even ppb) can persist in the final products. To that end, in a new study published in Green Chemical Engineering, a research published in Green Chemical Engineering (GreenChE) led by Prof Ri-Zhi Chen at Nanjing Tech University reported hierarchically porous N-doped carbon nanofiber membrane for continuous phenol hydrogenation to cyclohexanone.
“The acid/base etching selectively dissolves some of the in-situ generated SiO2 and ZnO NPs within the CNFM, significantly enhancing the membrane’s porosity,” explains explained lead author Prof Ri-Zhi Chen. “the remaining SiO2 and ZnO NPs embedded within the nanofibers contribute to the CNFM's flexibility.”
In this study, by investigating etching strategy and concentrations of the acid and base solutions, the researchers tailored the Pd/CNFM microstructure and performance, to synthesize electrospun carbon nanofiber membranes with abundant hierarchical pores, enriched pyrrolic nitrogen.
“Notably, the optimized membrane, Pd/CNFM-31.8A-9.1B, exhibited excellent catalytic performance and stability in the selective hydrogenation of phenol, achieving a high phenol conversion of 84.59% and a cyclohexanone selectivity of 91.72% over 25 h,” explains Chen. “Importantly, the structural integrity and catalytic efficiency of the Pd/CNFM-31.8A-9.1B membrane were well-maintained during continuous operation for an extended period of 75 h.”
The researchers noted that the inherent nanofiber structure of the membrane facilitated facile separation from the reaction solution, addressing a key challenge in traditional catalytic systems, showcasing the strong potential for continuous and energy-efficient industrial cyclohexanone production.
About GreenChE
GreenChE focuses on the significant cutting-edge research and the latest technological advances in core areas of green and sustainable development of chemistry and chemical engineering as well as in other relevant disciplines.
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Journal
Green Chemical Engineering
Article Title
Pd-decorated hierarchically porous N-doped carbon nanofiber membrane for continuous phenol hydrogenation to cyclohexanone
COI Statement
The authors declare that they have no known competing financial interests or person, relationships that could have appeared to influence the work reported in this paper.