Acid Strength of H3PW x Mo12−x O40 and H6P2W x Mo18−x O62 Heteropolyacid Catalysts as a Probe of Acid Catalysis for 2-Propanol Conversion Reaction

Abstract. Heteropoly compounds in the solid state are ionic crystals (sometimes amorphous) consisting of large polyanions, cations, water of crystallization, and other molecules. Heteropolyacids (HPAs) have several advantages as catalysts. On the one hand, they have a very strong Brønsted acidity, especially the cobalt and cesium salts; on the other hand they are exhibiting fast reversible multielectron redox transformations under mild conditions. The cobalt and cesium salts of wellsDawson HPAs were synthesized and characterized using elemental analysis and spectroscopic techniques ( 31 P-NMR, FT-IR). The wells-Dawson anions possess the ability to accept or release electrons through an external potential or upon exposure to UV radiation (photochemical reactions). The catalytic tests of these salts were investigated on phenol degradation where the UV photodegradation of acidified aqueous solutions (pH = 2) were studied in a batch photoreactor under ambient temperature and continuous circulation of phenol solution. The results reveal high catalytic activity for two HPAs, the best catalyst is the salt of cesium; where the presence of cesium improves significantly both the photcatalytic activity and the selectivity to oxalic acid.

show abstract

“…All the chemicals were of high-purity grade and were used as received. HCl, Na 2 SO 4 , Li 2 4 or NaOH (Prolabo).…”

Section: Chemicalsmentioning

confidence: 99%

“…Particular attention has been given to redox property can be tuned by replacing protons or by substituting framework transition-metal atoms with different metals [2].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization of cesium and cobalt substituted wells–Dawson heteropolyoxotungstates salts and their photocatalytic applications

Balaska¹,

Belghiche

Samar

et al. 2013

MATEC Web of Conferences

View full text Add to dashboard Cite

show abstract

Effect of Cs x H3−x PW12O40 addition on the catalytic performance of ZnFe2O4 in the oxidative dehydrogenation of n-butene to 1,3-butadiene

Lee

Kim

Chung

et al. 2009

Korean J. Chem. Eng.

Self Cite

View full text Add to dashboard Cite

Oxidative dehydrogenation of n-butene to 1,3-butadiene over ZnFe 2 O 4 catalyst mixed with Cs x H 3−x PW 12 O 40 heteropolyacid (HPA) was performed in a continuous flow fixed-bed reactor. The effect of Cs x H 3−x PW 12 O 40 addition on the catalytic performance of ZnFe 2 O 4 was investigated. Cs x H 3−x PW 12 O 40 itself showed very low catalytic performance in the oxidative dehydrogenation of n-butene. However, addition of small amount of Cs x H 3−x PW 12 O 40 into ZnFe 2 O 4 enhanced the catalytic performance of ZnFe 2 O 4 catalyst. The catalytic performance of ZnFe 2 O 4 -Cs x H 3−x PW 12 O 40 mixed catalysts was closely related to the surface acidity of Cs x H 3−x PW 12 O 40 . Among the catalysts tested, ZnFe 2 O 4 -Cs 2.5 H 0.5 PW 12 O 40 mixed catalyst showed the best catalytic performance. Strong acid strength and large surface acidity of Cs 2.5 H 0.5 PW 12 O 40 was responsible for high catalytic performance of ZnFe 2 O 4 -Cs 2.5 H 0.5 PW 12 O 40 mixed catalyst. Thus, Cs 2.5 H 0.5 PW 12 O 40 could be utilized as an efficient promoter and diluent in formulating ZnFe 2 O 4 catalyst for the oxidative dehydrogenation of n-butene.

show abstract

Inorganic heterogeneous catalysts for biodiesel production from vegetable oils

Endalew

Kiros

Zanzi

2011

Biomass and Bioenergy

322

163

View full text Add to dashboard Cite

Acid Strength of H3PW x Mo12−x O40 and H6P2W x Mo18−x O62 Heteropolyacid Catalysts as a Probe of Acid Catalysis for 2-Propanol Conversion Reaction

Cited by 4 publications

References 27 publications

Synthesis, characterization of cesium and cobalt substituted wells–Dawson heteropolyoxotungstates salts and their photocatalytic applications

Synthesis, characterization of cesium and cobalt substituted wells–Dawson heteropolyoxotungstates salts and their photocatalytic applications

Effect of Cs x H3−x PW12O40 addition on the catalytic performance of ZnFe2O4 in the oxidative dehydrogenation of n-butene to 1,3-butadiene

Inorganic heterogeneous catalysts for biodiesel production from vegetable oils

Contact Info

Product

Resources

About