(621h) The One Step Oxidation of Methanol to Dimethoxymethane on V2O5/CeO2 Catalysts

The One Step Oxidation of Methanol to
Dimethoxymethane on V₂O₅/CeO₂ Catalysts

Heqin Guo^a, Bo Hou^a,
Litao Jia^a, Debao Li^a*

^a State Key Laboratory of Coal
Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan,
030001, China.

*Corresponding author: Tel. /Fax: +86
351 4040410. E-mail addresses: dbli@sxicc.ac.cn

Dimethoxymethane
(CH₃OCH₂OCH₃), as an important chemical
intermediate, was widely used as diesel additive and building block in organic
synthesis. Generally, DMM is produced by the
two-stage synthesis. Such a flow chart could lead to a high cost, which
inhibits the application of DMM. Compared with
the two-step technique, the one-stage technique can synthesize DMM on the bi-founctional (employing redox sites and acidic sites) catalysts (3CH₃OH + 1/2O₂ °úCH₃OCH₂OCH₃
+ 2H₂O). This technique is expected to avoid the drawback of the
two-stage production.

In the present study, the V₂O₅/CeO₂
catalysts with different V₂O₅
content were prepared by the Sol-Gel method and characterized by XRD, BET,
Raman, NH₃-TPD and H₂-TPR
techniques. The catalytic properties were evaluated by the one-step oxidation
of methanol to dimethoxymethane. The results showed that the vanadium was
monolayer dispersed as V₂O₅ content was 15 wt%, aggregated as V₂O₅ crystalline
above 20 wt% and formed CeVO₄ at 30 wt%. The higher dispersion of vanadium can lead to
stronger reducibility and more acidic sites, which were closely
related to the higher methanol conversion and
dimethoxymethane (DMM) selectivity.

Keywords: Vanadia-cerium catalyst; Methanol oxidation reaction;
Acidity; Redox; Dimethoxymethane