摘要
用正戊醇和仲戊醇还原ＶＯＰＯ４·２Ｈ２Ｏ，以制备正丁烷氧化制顺酐的ＶＰＯ催化剂前驱物ＶＯＨＰＯ４·０．５Ｈ２Ｏ，并用ＸＲＤ、ＴＧ、ＳＥＭ对其进行了表征．结果表明，由正戊醇还原ＶＯＰＯ４·２Ｈ２Ｏ合成的前驱物ＶＯＨＰＯ４·０．５Ｈ２Ｏ的ＸＲＤ，在（２２０）晶面衍射强度较强；而由仲戊醇合成的前驱物ＶＯＨＰＯ４·０．５Ｈ２Ｏ的ＸＲＤ，在（００１）晶面衍射强度较强．正戊醇还原ＶＯＰＯ４·２Ｈ２Ｏ合成的前驱物ＶＯＨＰＯ４·０．５Ｈ２Ｏ，在空气＋１．５％（体积分数）正丁烷气氛中活化，仅形成活性相（ＶＯ）２Ｐ２Ｏ７；而由仲戊醇合成的前驱物，活化后，形成δ，αＶＯＰＯ４相和少量的活性相（ＶＯ）２Ｐ２Ｏ７．正丁烷催化氧化的性能研究表明，由正戊醇还原制备的前驱物活化后，其正丁烷转化率和顺酐选择性均比仲戊醇制备的高。
VOHPO 4·0.5H 2O, which is precursor of V P O catalyst for n butane to maleic anhydride, is prepared by reducing VOPO 4·2H 2O with pentan 1 ol and pentan 2 ol and charecterized through the combination of XRD, IR, TG and SEM techniques. VOHPO 4·0.5H 2O with rose like type structure prepared from pentan 1 ol comprises crystals, for which the (220) reflection is virtually the only feature of the diffraction pattern. It is transfomed under the activation conditions (703 K, 1.5% n butane in air) topotactically to (VO) 2P 2O 7 with high surface area (33.2 m 2/g) and catalytic performance for n butane oxidation to maleic anhydride as compared to VOHPO 4·0.5H 2O derived from V 2O 5/isobutanol/85% H 3PO 4. Whereas VOHPO 4·0.5H 2O prepared from pentan 2 ol gives crystals, for which the (001) reflection is the dominent feature of the diffraction; VOHPO 4·0.5H 2O with platelet type structure derived from pentan 2 ol is tansformed under activation conditions topotactically to δ,α VOPO 4 and a little (VO) 2P 2O 7, that result in a final catalyst with lower surface area( 12.4 m 2/g ) and catalytic perfopmance as compared to VOHPO 4·0.5H 2O prepared from pentan 1 ol.
出处
《分子催化》
EI
CAS
CSCD
北大核心
1998年第4期285-291,共7页
Journal of Molecular Catalysis(China)
关键词
钒磷氧化物
制备
正丁烷
氧化
顺酐
催化剂
VOHPO 4·0.5H 2O, Preparation, Catalytic performance, VOPO 4·2H 2O
