Improved Catalytic Performance toward Selective Oxidation of Benzyl Alcohols Originated from New Open‐Framework Copper Molybdovanadate with a Unique V/Mo Ratio
Yuquan Feng, Zhiguo Zhong, Shuyang Chen, Kecheng Liu, Zhaohui Meng
Abstract
Abstract A new organic‐inorganic hybrid open‐framework molybdovanadate with mixed‐valences of vanadium (V 4+ /V 5+ =4/3) and molybdenum (Mo 5+ /Mo 6+ =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: H 2 O 2 , 30 wt %) have been well evaluated. The results indicated that it exhibited improved catalytic activities (conv.: 96.8 %) compared with the catalyst (Cpyr) 5 PV 2 Mo 5 W 5 O 40 [conv.: 88.51 %, Cpyr=(C 16 H 32 C 5 H 4 N) + )], 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, −CH 3 , −OCH 3 and −Cl) were significantly higher than those of the substrate containing electron withdrawing group (−NO 2 ) (conv. 67.4 %; sele.: 80.8 %). This is due to the fact that the −NO 2 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.