Revealing the Effect of Mass Transfer on Direct Dehydrogenation of Ethylbenzene Catalyzed by Phosphorous-doped Boron Nitride: Comparative Study

Phosphorous-doped boron nitride (PBN) was previously confirmed to be an effective metal-free catalyst for the challenging topic of ethylbenzene direct dehydrogenation (DDH) to styrene. Here, the effect of mass transfer factors including the porosity and surface exposure degree of mesoporous-PBN (m-PBN) on its performance over DDH was investigated by control experiments. The central pore size of m-PBN was closely dependent on the thiourea amount and heating rate. The m-PBN with optimal pore size delivered a significantly improved styrene production rate of 21.47 mmol(ST) g(-1) h(-1) and styrene selectivity over 98 %. Further, when m-PBN was in-situ grown on cordierite, the activity and stability of catalyst could be further enhanced to 27.08 mmol(ST) g(-1) h(-1) for 50 h stable run, which presented a promising industrial application prospect. This paper justified that the mass transfer factors involved in two-dimensional metal-free catalysts were crucial for DDH of ethylbenzene.

Automated summary

The mass transfer factors in two-dimensional metal-free catalysts were found to be crucial for the direct dehydrogenation of ethylbenzene. Phosphorous-doped boron nitride (PBN) was confirmed as an effective metal-free catalyst for producing styrene.