Novel Catalysts Effective for Dehydrofluorination of CF3CH3 (HFC143a) into CF2CH2

Abstract

The catalytic dehydrofluorination of CF3CH3 into CF2CH2 was studied over various metal phosphates in a fixed-bed reactor. The Mg2P2O7 catalyst exhibited moderate activity, higher selectivity and greater stability. The active sites for CF2CH2 formation are weak acid sites of the catalysts.

Metal Phosphate-Supported Pt Catalysts for CO Oxidation

“…In the literature, some metal carbonates, phosphates, and sulfates have been used as supports to load metals [2]. From the examples on the catalytic applications of metal phosphate-based catalysts cited in the Introduction section [4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,…”

“…In a classic book written by Tanabe, Misono, Ono, and Hattori, metal phosphates are highlighted as a new family of solid acids showing some promising applications in heterogeneous catalysis [3]. Metal phosphates can be used as catalysts directly, for instance, in the partial oxidation of propane [4], oxidative dehydrogenation of isobutane to isobutene [5,6,7], oxidative dehydrogenation of ethylbenzene to styrene [8], dehydration of cyclohexanol and 1-methylcyclohexanol [9,10,11], retro-Prins reaction [12,13], terpene rearrangements [14], alkylation of anisole with alcohols [15], dehydrofluorination of CF 3 CH 3 into CF 2 CH 2 [16,17], hydrolysis of CCl 2 F 2 [18,19,20], decomposition of CF 4 [21,22], decomposition of CH 2 FCF 3 [23], decomposition of chlorobenzene [24], decomposition of SF 6 [25,26], and hydrolysis of NF 3 [27]. …”

Highly Selective Dehydrochlorination of 1,1,1,2‐Tetrafluoro‐2‐chloropropane to 2,3,3,3‐Tetrafluoropropene over Alkali Metal Fluoride Modified MgO Catalysts

“…The chemistry of gas‐phase β‐elimination over solid catalysts has been well established on alkyl halides (RX) with different α‐leaving groups and/or β‐substituents . However, there were few academic articles on the selective dehydrohalogenation of haloalkanes with more than one halogen leaving groups on the same C α atom.…”

Catalytic Dehydrofluorination of Hydrofluoroalkanes to Fluorinated Olifein Over Ni/AlF3 Catalysts

“…The activity of AlF3 catalyst decline with time on stream, the long-chain fluorocarbons and/or coke coving the Lewis acid centres might result in deactivation of catalysts. The long-chain fluorocarbons and coke derived from the coupling and cracking of carbonpositive ion intermediates [13], carbon-positive ion intermediate generated by cleavage of C-F bond over strong Lewis acid sites which considering as the first step [12]. The Ni/AlF3 catalysts possessed good activity and stability, it may be due to the fact that Ni restrain the formation of carbon-positive ion intermediate through the synergistic catalysis.…”

“…Teinz et al [12] argued that AlF3 belonged to Lewis acid was an effective De-HF catalyst, and the interaction between Lewis acid sites and fluorine atom initiates the De-HF. Li et al [13] suggested that the weak Lewis acid sites on the P2O7 4-salt is the reaction center, it proposed that the carboniumion mechanism over the Mg2P2O7 catalyst for De-HF of 1, 1, 1-trifluoroethane(CF3CH3) to vinylidene fluoride. Dehydrofluorination of HFCs should involve the cleavage of C-F and C-H bond.…”