Selective ethanol synthesis via multi-step reactions from syngas: Ferrierite-based catalysts and fluidized-bed reactor application

Catalytic Decomposition of Pyrolysis Fuel Oil over in Situ Carbon-Coated Ferrierite Zeolite for Selective Hydrogen Production

“…25,28,29 The relative crystallinities were found to be in the range of 47−100%, where the FER(8) showed a lower crystallinity with the presence of abundant defect sites such as the Lewis acidic extra-framework Al species possibly which were related to preferential formations of amorphous coke precursors. 18,25 The surface acidity of the asprepared FER zeolites was also verified by NH 3 -TPD analysis, and desorption patterns of NH 3 molecules are displayed in Figure 1D. Two characteristic desorption peaks of NH 3 were clearly observed at the maximum temperature range of 185− 200 °C and ∼440 °C, which can be assigned to weak and strong acidic sites, respectively.…”

“…The characteristic pristine FER structures were well synthesized on all the FER zeolites, and their relative crystallinities are summarized in Table . With an increase of Si/Al molar ratios, the most intense characteristic diffraction peaks at 2θ = 9.3 and 25.2° were increased steadily, which suggests an increased crystallinity by forming well-developed 8- and 10-MR micropore structures of the FER zeolite. ,, The relative crystallinities were found to be in the range of 47–100%, where the FER(8) showed a lower crystallinity with the presence of abundant defect sites such as the Lewis acidic extra-framework Al species possibly which were related to preferential formations of amorphous coke precursors. , The surface acidity of the as-prepared FER zeolites was also verified by NH 3 -TPD analysis, and desorption patterns of NH 3 molecules are displayed in Figure D. Two characteristic desorption peaks of NH 3 were clearly observed at the maximum temperature range of 185–200 °C and ∼440 °C, which can be assigned to weak and strong acidic sites, respectively.…”

“…Various homemade FER zeolites were previously synthesized as Na + -form FER with different Si/Al molar ratios from 8 to 20 by a hydrothermal synthesis method. 18 For more details, the mixed solution of SiO 2 /NaAlO 2 /SDA/NaOH/deionized water (DIW) was prepared at a molar ratio of 1:y:0.9:0.14:40 (where, the y value was changed according to Si/Al molar ratios of FER) by using the precursors of fumed silica (SiO 2 ), sodium aluminate (NaAlO 2 ), and piperidine (hexahydropyridine, C 5 H 11 N) as the sources of silica and alumina and structure-directing agent (SDA) for the synthesis of the FER zeolites, respectively. The mixed solution was completely stirred for more than 12 h, and it was further used to synthesize the Na + -form FER zeolites in a batch reactor for 7 days.…”

“…The PFO can selectively produce pure hydrogen with a simultaneous production of solid cokes by the simplified reaction of C n H m → n C + ( m /2)­H 2 on various heterogeneous solid-acid catalysts such as ZSM-5, Y, or ferrierite (FER) zeolites having regular micropores with large amounts of acidic sites. In addition, the acidic sites of zeolites can be easily modified and controlled using an ion-exchange method with various metal ions according to the types of catalytic reactions to enhance catalytic activity and stability. − Since the amount and strength of the acid sites on the zeolites can be easily adjusted according to molar ratios of Si/Al, − the effects and roles of the surface acidity to catalytic activity and stability have been largely investigated for various catalytic reactions related to severe depositions of coke precursors. Interestingly, many carbon materials such as carbon black and carbon nanotubes having surface defect sites have been recently investigated as active heterogeneous catalysts for the decomposition of hydrocarbons to produce pure hydrogen without significant production of CO 2 . − Especially, FER zeolite was selected as a candidate for PFO pyrolysis due to its relatively planar pore structures composed of the 8-membered ring (8-MR) and 10-membered ring (10-MR) structures with a larger amount of moderate acidic sites compared to other zeolites such as ZSM-5 and Mordenite, ,− which seems to have a beneficial effect for a higher stability through a small formation of inactive heavy coke precursors.…”

Direct Conversion of CO2 into Dimethyl Ether over Al2O3/Cu/ZnO Catalysts Prepared by Sequential Precipitation

“…Although different from the condition for DME carbonylation reported in literature (usually below 450 K and 20 bar [20,21]), the finding seemed to be compatible with our test condition. The activity test was performed in a dual-bed catalyst system using the SP-derived catalyst and zeolite ferrierite (FER@FER) recently developed by a seed method [22], where the latter catalyst of 2.0 g was placed right after the bed of 0.6 g SP-60 or SP-80 ( Table 5). The dual-bed of SP-60 and FER@FER at 573 K and 50 bar showed the increase in DME selectivity (82.2%) and the decrease in methanol selectivity (10.5%) compared to only SP-60 under the same reaction condition.…”