Surface structure and activity of iron molybdate catalyst for methanol oxidation to formaldehyde

doi:10.11949/j.issn.0438-1157.20160132

Abstract

Abstract:

Iron-molybdenum catalysts with the same atomic ratio of Mo/Fe for methanol oxidation to formaldehyde were prepared by co-precipitation method under varied rates of stirring. The catalysts were characterized by SEM, XRD and Raman spectrum and the catalytic activity and selectivity evaluated in a fixed-bed reactor.It showed that with an increase of stirring speed, the specific surface area of the catalysts increases and the catalytic activity enhances. The yield of formaldehyde increases from 73.8% at 600 r·min^-1 to 95.7% (T=280℃) at 10000 r·min^-1. The catalyst consists of plate-like MoO₃ and amorphous sponge-like Fe₂(MoO₄)₃. In addition, the catalyst consists of sheet-shaped MoO₃ and particle-shaped Fe₂(MoO₄)₃, of which the former had barely no activity, and only the combination of the former and the latter (Fe₂(MoO₄)₃) does show the catalytic activity.

Key words: methanol oxidation, formaldehyde, iron molydbate, precipitation, preparation, surface structure, activity

摘要：

利用共沉淀法在不同搅拌速度下制备了相同Mo/Fe原子比的甲醇氧化制甲醛催化剂，采用SEM、XRD和拉曼光谱等对催化剂进行表征，在固定床微反上评价催化剂活性和选择性。结果表明，搅拌速度增大，催化剂比表面积增大，催化活性增强，甲醛收率由600 r·min^-1时的73.8%增加到10000 r·min^-1时的95.7%（280℃）。此外，催化剂由片状的MoO₃和颗粒状的Fe₂（MoO₄）₃两部分组成，游离的片状MoO₃无明显催化活性，只有与Fe₂（MoO₄）₃结合时才具有催化活性。

关键词: 甲醇氧化, 甲醛, 铁钼催化剂, 沉淀, 制备, 表面结构, 活性

CLC Number:

O643

ZHANG Shuai, ZHANG Yike, HU Rlckt, ZHEN Bin, HAN Minghan. Surface structure and activity of iron molybdate catalyst for methanol oxidation to formaldehyde[J]. CIESC Journal, 2016, 67(9): 3678-3683.

张帅, 张一科, 呼日勒朝克图, 甄彬, 韩明汉. 甲醇氧化制甲醛铁钼催化剂表面结构与活性[J]. 化工学报, 2016, 67(9): 3678-3683.

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