Kendell, Shane; Brown, Trevor Colin; Burns, Robert C

Author(s)

Kendell, Shane

Brown, Trevor Colin

Burns, Robert C

Publication Date

2008

Abstract

A low-pressure steady-state technique has been used to investigate the rates and mechanisms of the oxidation of isobutane over H₃[PMo₁₂O₄₀], CuH₄[PMo₁₂O₄₀]₂, Cu₂H₂[PMo₁₂O₄₀]₂, Cu₂.₅H[PMo₁₂O₄₀]₂, and Cu₃[PMo₁₂O₄₀]₂. Observed oxidation products over all catalysts are methacrolein, 3-methyl-2-oxetanone, acetic acid, carbon dioxide and water. The most selective catalyst for methacrolein formation at low temperatures (<496°C) is Cu₂.₅H[PMo₁₂O₄₀]₂, where both Cu(II) reduction and acid sites play a role. The least active catalyst at low temperatures is phosphomolybdic acid followed by Cu₃[PMo₁₂O₄₀]₂. This activity is reversed at higher temperatures. The 3-methyl-2-oxetanone is a unique product and is likely to be the precursor to methacrylic acid. Acetic acid is also probably a precursor to complete oxidation. Catalyst deactivation or restructuring is significant only over H₃[PMo₁₂O₄₀].

Citation

Catalysis Today, 131(1-4), p. 526-532

ISSN

1873-4308

0920-5861

Link

https://hdl.handle.net/1959.11/1593

Publisher

Elsevier BV

Title

Accurate low-pressure kinetics for isobutane oxidation over phosphomolybdic acid and copper(II) phosphomolybdates

Type of document

Journal Article

Entity Type

Publication

Author(s)	Kendell, Shane Brown, Trevor Colin Burns, Robert C
Publication Date	2008
Abstract	A low-pressure steady-state technique has been used to investigate the rates and mechanisms of the oxidation of isobutane over H₃[PMo₁₂O₄₀], CuH₄[PMo₁₂O₄₀]₂, Cu₂H₂[PMo₁₂O₄₀]₂, Cu₂.₅H[PMo₁₂O₄₀]₂, and Cu₃[PMo₁₂O₄₀]₂. Observed oxidation products over all catalysts are methacrolein, 3-methyl-2-oxetanone, acetic acid, carbon dioxide and water. The most selective catalyst for methacrolein formation at low temperatures (<496°C) is Cu₂.₅H[PMo₁₂O₄₀]₂, where both Cu(II) reduction and acid sites play a role. The least active catalyst at low temperatures is phosphomolybdic acid followed by Cu₃[PMo₁₂O₄₀]₂. This activity is reversed at higher temperatures. The 3-methyl-2-oxetanone is a unique product and is likely to be the precursor to methacrylic acid. Acetic acid is also probably a precursor to complete oxidation. Catalyst deactivation or restructuring is significant only over H₃[PMo₁₂O₄₀].
Citation	Catalysis Today, 131(1-4), p. 526-532
ISSN	1873-4308 0920-5861
Link	https://hdl.handle.net/1959.11/1593
Publisher	Elsevier BV
Title	Accurate low-pressure kinetics for isobutane oxidation over phosphomolybdic acid and copper(II) phosphomolybdates
Type of document	Journal Article
Entity Type	Publication

Accurate low-pressure kinetics for isobutane oxidation over phosphomolybdic acid and copper(II) phosphomolybdates

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