ScholarWorks@성균관대학교

초록

Herein, the conversion of tetrahydrofurfuryl alcohol (THFA) and furfuryl alcohol (FAL)—hydrogenation products of furfural (FUR)—to 1,5-pentanediol (1,5-PDO) is investigated using a mixed metal oxide catalytic system composed of CoOx, MgO, and Al2O3. Different types of active sites are analyzed to establish correlations between catalyst structure and performance. Upon reduction, CoO forms the metallic species Co0 and coordinatively unsaturated Co2+ near O vacancies (OVs). These Co2+ Lewis acid sites adsorb ether and hydroxyl O atoms from FAL and THFA, thereby weakening or cleaving the C2–O1 bond via coordination interactions. Simultaneously, H activated at the Co0 sites undergoes spillover to the adsorbed intermediates, promoting hydrogenolysis and 1,5-PDO generation. At higher reduction temperatures, catalytic activities for both FAL and THFA transformations are enhanced due to the increase in the number and proximity of Co2+/OV sites, which favor strong dual-site adsorption via the η2-(O1, O2) coordination mode. In the case of FAL, this higher concentration of Co2+/OV sites also promotes higher selectivity toward 1,5-PDO. MgO provides basic sites that enhance strong reactive molecule adsorption probably via deprotonation, whereas Al2O3 increases surface area and thus catalytic activity. Although the use of FAL as the reactant results in significantly higher productivity as compared to the case of THFA (FAL: 30.6 mmol1,5-PDO gcat.−1 h−1 vs. THFA: 0.3 mmol1,5-PDO gcat.−1 h−1), this higher productivity is achieved with the loss of 1,5-PDO selectivity, which is considerably lower (selectivity from FAL: 45.9 % vs. selectivity from THFA: 81.8 %).

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