Synthesis of cis-1,3,3,3-tetrafluoropropene by catalytic isomerization of trans-1,3,3,3-tetrafluoropropene over alumina catalysts

Basicity-Induced Trans-1,3,3,3-tetrafluoropropene Isomerization on Alkaline Earth Metal Fluoride Catalysts

“…For the dehydrofluorination reaction of fluoroalkanes, it is usually considered that the active site is the Lewis acid site on the catalyst surface. , Therefore, we speculate that the formation of CF 3 CCH through the dehydrofluorination of CF 3 CH = CHF is associated with the surface acid–base properties of the prepared metal fluorides. Different from aluminum fluoride, no significant hydrogen fluoride addition activities are found for the alkaline earth metal fluorides. The selectivity of HFC–245fa is less than 0.5%, which is beneficial to the separation of products.…”

“…Limited by thermodynamic equilibrium, the isomerization conversion of HFO−1234ze(E) is less than 28% at 350 °C. 13 MgF 2 , CaF 2 , and BaF 2 -2 are found to be highly active in comparison with the remaining catalysts, with conversions over 18% in the first 20 min. By comparing the reactivity and selectivity among various catalysts, it could be found that the MgF 2 and BaF 2 -2 samples exhibited superior catalytic performance, with the yield of the HFO−1234ze(Z) product measured to be 17.8 and 18.3%, respectively.…”

“…12 Using the above synthesis routes, HFO−1234ze was obtained as a mixture of both trans-and cis-isomers, which results in an HFO−1234ze(Z) selectivity of only 10% ∼ 23%. 13 In addition to the above reaction pathways, the isomerized transformation of HFO−1234ze is considered as a highly efficient synthesis route to obtain one certain isomer. Okamoto et al have fully investigated the HFO−1234ze(E) isomerization to HFO− 1234ze(Z) over Al, Cr, Mn, Zr, Ti, or Mg metal fluorides, with the results also demonstrating the low selectivity of HFO− 1234ze(Z) due to the formation of an azeotropic-like composition of HFC−245fa.…”

Pyrolysis Behavior of Pyrite under a CO–H2 Atmosphere

“…Figure 7 shows the mass spectrometry (MS) results during the pyrolysis of pyrite; the inorganic compounds with m / z = 32, 34, 60, 64, and 76 were detected during the experiments. According to previous analysis, 37 FeS 2 catalyzes the reaction of H 2 and CO to produce methanol ( m / z = 34) only at low temperatures, while the temperature in this experiment is higher than 400 °C, lacking the generating conditions of methanol, and m / z = 34 therefore represents H 2 S. As the gases in the experiment are H 2 and CO, oxygen cannot exist stably in such a strong reducing atmosphere, so m / z = 32 represents sulfur monomers. As discussed in Figure 6 , the sulfur monomers generated from FeS 2 will immediately react with H 2 or CO under current experimental conditions, so the signal of sulfur in the mass spectrum is the m / z = 32 signal produced by the experimental gas molecules after electron bombardment.…”

Syngas production at a near-unity H2/CO ratio from photo-thermo-chemical dry reforming of methane on a Pt decorated Al2O3–CeO2catalyst

“…In light of these two studies, it seems that an improved H 2 /CO ratio can be achieved by coupling a catalyst with a weak acidic promoter. In this sense, Al 2 O 3 , a type of abundant and low-cost chemical compound with intrinsic mild acidic characteristics 33,34 that has long been in catalyst design in a number of industrial processes including hydrocarbon isomerization, 34 catalytic cracking, 35 etc. , can be an ideal addition on DRM catalysts to improve hydrogen production selectivity in the DRM process.…”