Improved Catalytic Performance toward Selective Oxidation of Benzyl Alcohols Originated from New Open‐Framework Copper Molybdovanadate with a Unique V/Mo Ratio

• Published in: Chemistry : a European journal 2023-11, Vol.29 (65), p.e202302051-n/a
• Main Authors: Feng, Yuquan, Zhong, Zhiguo, Chen, Shuyang, Liu, Kecheng, Meng, Zhaohui
• Format: Article
• Language: English
• Subjects: Benzaldehyde; Benzyl alcohol; benzyl alcohols; Catalysts; Cations; Chemistry; ferromagnetic interaction; Hydrogen peroxide; improved catalytic activity; mechanism; Molybdenum; molybdovanadate; Nitrogen dioxide; Oxidants; Oxidation; Oxidizing agents; Recyclability; Structural stability; Substrates; Vanadium
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202302051

A new organic‐inorganic hybrid open‐framework molybdovanadate with mixed‐valences of vanadium (V4+/V5+=4/3) and molybdenum (Mo5+/Mo6+=8/2) cations has been synthesized. The complex possesses the unique V/Mo ratio (7/10), fascinating 8‐C topological network and 1D 4‐MR channels (7.793 Å×6.699 Å). Importantly, its catalytic activities for the selective oxidation of benzyl alcohol to benzaldehyde (oxidant: H2O2, 30 wt %) have been well evaluated. The results indicated that it exhibited improved catalytic activities (conv.: 96.8 %) compared with the catalyst (Cpyr)5PV2Mo5W5O40 [conv.: 88.51 %, Cpyr=(C16H32C5H4N)+)], high recyclability and structural stability. Moreover, the conversions and selectivities (conv.: 82.4–92.5 %; sele.: 91.5–95.7 %) of the substrates containing electron donating groups (−OH, −CH3, −OCH3 and −Cl) were significantly higher than those of the substrate containing electron withdrawing group (−NO2) (conv. 67.4 %; sele.: 80.8 %). This is due to the fact that the −NO2 with a large Hammett substituent constant is not conducive to the generation of transition state products. The studies revealed the complex could act as a highly efficient heterogeneous catalyst in selective oxidation of benzyl alcohols. A copper molybdovanadate with mixed‐valent vanadium (V4+/V5+=4/3) and molybdenum (Mo5+/Mo6+=8/2) cations exhibits improved catalytic activity (conv.: 96.8 %) compared with the complex (Cpyr)5PV2Mo5W5O40 [conv.: 88.51 %, Cpyr=(C16H32C5H4N)+)] and could serve as a highly efficient heterogeneous catalyst in the selective oxidation of benzyl alcohols to benzaldehydes.