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Preparation of Highly Active Monometallic Rhenium Catalysts for Selective Synthesis of 1,4‐Butanediol from 1,4‐Anhydroerythritol
Author(s) -
Wang Tianmiao,
Tamura Masazumi,
Nakagawa Yoshinao,
Tomishige Keiichi
Publication year - 2019
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201900900
Subject(s) - catalysis , chemistry , yield (engineering) , reactivity (psychology) , solvent , reaction conditions , isomerization , rhenium , organic chemistry , materials science , metallurgy , medicine , alternative medicine , pathology
1,4‐Butanediol can be produced from 1,4‐anhydroerythritol through the co‐catalysis of monometallic mixed catalysts (ReO x /CeO 2 +ReO x /C) in the one‐pot reduction with H 2 . The highest yield of 1,4‐butanediol was over 80 %, which is similar to the value obtained over ReO x –Au/CeO 2 +ReO x /C catalysts. Mixed catalysts of CeO 2 +ReO x /C showed almost the same performance, giving 89 % yield of 1,4‐butanediol. The reactivity trends of possible intermediates suggest that the reaction mechanism over ReO x /CeO 2 +ReO x /C is similar to that over ReO x –Au/CeO 2 +ReO x /C: deoxydehydration (DODH) of 1,4‐anhydroerythritol to 2,5‐dihydrofuran over ReO x species on the CeO 2 support with the promotion of H 2 activation by ReO x /C, isomerization of 2,5‐dihydrofuran to 2,3‐dihydrofuran catalyzed by ReO x on the C support, hydration of 2,3‐dihydrofuran catalyzed by C, and hydrogenation to 1,4‐butanediol catalyzed by ReO x /C. The reaction order of conversion of 1,4‐anhydroerythritol with respect to H 2 pressure is almost zero and this indicates that the rate‐determining step is the formation of 2,5‐dihydrofuran from the coordinated substrate with reduced Re in the DODH step. The activity of ReO x /CeO 2 +ReO x /C is higher than that of ReO x –Au/CeO 2 +ReO x /C, which is probably related to the reducibility of ReO x /C and the mobility of the Re species between the supports. High‐valent Re species such as Re 7+ on the CeO 2 and C supports are mobile in the solvent; however, low‐valent Re species, including metallic Re species, have much lower mobility. Metallic Re and cationic low‐valent Re species with high reducibility and low mobility can be present on the carbon support as a trigger for H 2 activation and promoter of the reduction of Re species on CeO 2 . The presence of noble metals such as Au can enhance the reducibility through the activation of H 2 molecules on the noble metal and the formation of spilt‐over hydrogen over noble metal/CeO 2 , as indicated by H 2 temperature‐programmed reduction. The higher reducibility of ReO x –Au/CeO 2 lowers the DODH activity of ReO x –Au/CeO 2 +ReO x /C in comparison with ReO x /CeO 2 +ReO x /C by restricting the movement of Re species from C to CeO 2 .