Title

Characterizations of partially reduced polyoxometalate catalysts using ammonia adsorption microcalorimetry and methanol oxidation studies / by Suresh Babu Bommineni.

Author

Suresh Babu Bommineni, Michigan Technological University

Date of Award

2011

Document Type

Master's Thesis

Degree Name

Master of Science in Chemical Engineering (MS)

College, School or Department Name

Department of Chemical Engineering

Advisor

Joseph H Holles

Abstract

Phosphomolybdic acid (H₃PMo₁₂O₄₀) along with niobium,pyridine and niobium exchanged phosphomolybdic acid catalysts were prepared. Ammonia adsorption microcalorimetry and methanol oxidation studies were carried out to investigate the acid sites strength acid/base/redox properties of each catalyst. The addition of niobium, pyridine or both increased the ammonia heat of adsorption and the total uptake. The catalyst with both niobium and pyridine demonstrated the largest number of strong sites. For the parent H₃PMo₁₂O₄₀ catalyst, methanol oxidation favors the redox product. Incorporation of niobium results in similar selectivity to redox products but also results in no catalyst deactivation. Incorporation of pyridine instead changes to the selectivity to favor the acidic product. Finally, the inclusion of both niobium and pyridine results in strong selectivity to the acidic product while also showing no catalyst deactivation. Thus the presence of pyridine appears to enhance the acid property of the catalyst while niobium appears to stabilize the active site.

Recommended Citation

Bommineni, Suresh Babu, "Characterizations of partially reduced polyoxometalate catalysts using ammonia adsorption microcalorimetry and methanol oxidation studies / by Suresh Babu Bommineni.", Master's Thesis, Michigan Technological University, 2011.

https://doi.org/10.37099/mtu.dc.etds/2