Measurement of the relative acid strength and acid amount of solid acids by argon adsorption

Matsuhashi, Hiromi; Arata, Kazushi

doi:10.1039/b316990a

Cited by 28 publications

(19 citation statements)

References 33 publications

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“…3). The second peak, in particular, may be closely related with surface acid properties 12) . The amount of NH3 adsorption over ; total pressure 0.1 MPa, 10 wt％ W/H-ZSM-5 0.5 g. b) Si/Al 2 ratio.…”

Section: Nh3-tpd Investigations Of La W/h-zsm-5 Andmentioning

confidence: 99%

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Effects of Surface Modification of H-ZSM-5 Catalysts on Direct Transformation of Ethanol into Lower Olefins

和久

仁

功

2008

J. Jpn. Petrol. Inst.

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Various H-ZSM-5 catalysts were assessed for ethanol conversion into lower olefins. Ethanol was converted to lower olefins over H-ZSM-5 catalyst without modification. The selectivities for ethylene and propylene were much lower than those for aromatics such as benzene, toluene, and xylene (BTX), and C1-C4 saturated hydrocarbons. Addition of W and La was found to reduce aromatization and olefin hydrogenation, and, under ethanol conversion of almost 100％ , the selectivity for propylene and ethylene was improved, whereas the selectivity for BTX was decreased. The amount of carbon deposit was almost the same as that without modification. The selectivity for propylene formation may be associated with the percentage of Brønsted acid sites on the catalyst surface.

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Section: Nh3-tpd Investigations Of La W/h-zsm-5 Andmentioning

confidence: 99%

“…Ammonia can be used as a probe molecule to explore the overall acid properties of the catalyst surface using temperature-programmed desorption (TPD) 12) . Thus, _…”

Section: Effects Of Additive On W-modified H-zsm-5mentioning

confidence: 99%

Effects of Surface Modification of H-ZSM-5 Catalysts on Direct Transformation of Ethanol into Lower Olefins

和久

仁

功

2008

J. Jpn. Petrol. Inst.

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“…The heats of Ar adsorption and the adsorption amounts calculated using the methods above are summarized in table 1 [28][29][30]. The catalysts denoted by JRC in Table 1 are reference catalysts supplied by the Reference Catalyst Committee of The Catalysis Society of Japan.…”

Section: Comparison Of the Calculation Methodsmentioning

confidence: 99%

Adsorption and desorption of small molecules for the characterization of solid acids

Matsuhashi

Arata

2006

Catal Surv Asia

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The relative acid strength and acid amount of solid acids has been determined from the adsorption and desorption of small molecules, such as argon. The order of activation energy for desorption of Ar from a solid acid, determined using temperatureprogrammed desorption (TPD), is sulfated zirconia > Cs 2.5 H 0.5 PW 12 O 40 > proton-type zeolites > silica-alumina. The adsorption isotherms were analyzed using Langmuir and Henry equations. The Henry-type adsorption isotherms were also analyzed using the theory of Cremer and Flu¨gge. The heat of Ar adsorption was 22 kJ mol )1 for sulfated zirconia and ca. 17 kJ mol )1 for mordenite, ZSM-5, and beta-zeolite. Molybdenum oxides reduced at 623 and 773 K exhibited a large heat of adsorption (19.3 and 19.7 kJ mol )1 , respectively), and these materials are classified as superacids. W-Nb mixed-oxides and tungstated tin oxide (calcined at 1373 K), which are newly developed solid acids, had a heat of adsorption of 18.1 and 16.9 kJ mol )1 , respectively. The type of acid site could be distinguished by comparing the heat of adsorption of Ar and N 2 . Our data indicate that Ar is useful for the characterization of solid acids.

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“…The application of different methods such as TPD [36], ammonia adsorption measurements [37] as well as the use of isobutane as a test reactant [19] to one solid acid i.e. ZrO 2 /SO 4 2-allow to state that the acid strength is in the range of -19 \ H O \ -18 while the results obtained using NMR technique [38,39], indicate that the acid strength was considerably lower than that of sulfuric acid (H O = -12).…”

Section: Other Methods For Acid Strength Determinationmentioning

confidence: 99%

Styrene and styrene dimer derivatives, cyclohexene, tert-butylbenzene and cumene as test reactions for acid strength measurements of crystalline and amorphous silica-aluminas, sulfated oxides and Amberlyst

Marczewski

Marczewska

Popielarska

et al. 2015

Reac Kinet Mech Cat

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The minimal H O values required for cyclohexene, a-methylstyrene, styrene, 2,4-diphenyl-4-methyl-1-pentene, 4-phenyl-1-butene, tert-butylbenzene and cumene to undergo the chosen test reactions over solid acids at 303 K have been established. The chosen reactions and the respective H O min values obtained are as follows: a-methylstyrene and styrene oligomerization (-3.3 and -5.3), 2,4-diphenyl-4-methyl-1-pentene and 4-phenyl-1-butene oligomerization and isomerization (-6.9 and -7.9), cyclohexene oligomerization (-7.8), tert-butylbenzene disproportionation (-10.8) and cumene disproportionation (-11.5). The above mentioned test reactions were used to study the acid strength of different solid acids.

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Measurement of the relative acid strength and acid amount of solid acids by argon adsorption

Cited by 28 publications

References 33 publications

Effects of Surface Modification of H-ZSM-5 Catalysts on Direct Transformation of Ethanol into Lower Olefins

Effects of Surface Modification of H-ZSM-5 Catalysts on Direct Transformation of Ethanol into Lower Olefins

Adsorption and desorption of small molecules for the characterization of solid acids

Styrene and styrene dimer derivatives, cyclohexene, tert-butylbenzene and cumene as test reactions for acid strength measurements of crystalline and amorphous silica-aluminas, sulfated oxides and Amberlyst

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