Catalysis Database

Chemisorptive and catalytic properties of V2O5 supported on phosphate modified γ-alumina

L, Jhansi Lakshmi and K, Narsimha and P, Kanta Rao (1993) Chemisorptive and catalytic properties of V2O5 supported on phosphate modified γ-alumina. Applied Catalysis A: General , 94 (1). pp. 61-70.

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Official URL: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TF5-43VCM16-39&_user=518931&_coverDate=01%2F27%2F1993&_alid=606058388&_rdoc=29&_fmt=full&_orig=search&_cdi=5217&_sort=d&_docanchor=&view=c&_ct=55&_acct=C000025838&_version=1&_urlVersion=0&_userid=

Abstract

γ-Alumina modified with phosphoric acid is used as a carrier to disperse and stabilise the active vanadia phase. Compared to conventional vanadia/γ-alumina catalysts, these catalysts showed high V2O5 dispersion even at a loading as high as 20 wt.-% V2O5 revealed by low-temperature oxygen chemisorption (LTOC) and X-ray diffraction (XRD) data. Ammonia chemisorption at 150°C was used to determine the acidity of vanadia catalysts supported on phosphate modified alumina. Electron spin resonance spectra of the reduced catalysts further confirmed the findings of LTOC and XRD. Ammonia uptake is correlated with the activity for the partial oxidation of methanol and the oxygen chemisorption data with selectivity for formaldehyde. Phosphorus addition in the form of phosphate acts as a promoter causing a beneficial effect in substantially improving the selectivity to formaldehyde.

Item Type:Article
Uncontrolled Keywords:ammonia adsorption; γ-alumina; catalyst characterization (ESR, LTOC, XRD); dispersion; phosphate modified γ-alumina; vanadia.
Subjects:Science > Chemistry
ID Code:1010
Deposited By:Prof Balasubramanian Viswanathan
Deposited On:05 Aug 2007 12:05
Last Modified:05 Aug 2007 12:05

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