Measurement of Heat of Argon Adsorption for the Evaluation of Relative Acid Strength of Some Sulfated Metal Oxides and H-type Zeolites

Matsuhashi, Hiromi; Tanaka, and Takae; Arata, Kazushi

doi:10.1021/jp0118017

Cited by 48 publications

(29 citation statements)

References 14 publications

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“…Matsuhashi et al found that the relative acid strength of sulfated alumina [43], sulfated SnO 2 , sulfated ZrO 2 , silicaalumina, H-Y, H-ZSM-5, and H-mordenite [44] can be estimated by the heat of Ar adsorption, calculated from a temperature dependence of amount of Ar adsorption around room temperature. They proposed that for evaluation of the surface acidity, TPD of argon is a very useful method [45].…”

Section: Ar-tpdmentioning

confidence: 99%

Review of SO 2− 4 /M x O y solid superacid catalysts

Liao

2009

Front. Chem. Eng. China

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Some metal oxides modified with sulfate ions form highly acidic or superacidic catalysts. SO 2 -4 =M x O y solid superacid catalysts, play a vital role in more and more fields such as organic synthesis, fine chemicals, pharmaceuticals, and means for strengthening environmental safeguards. This review highlights the recent development of solid superacid catalysts based on SO 2 -4 =M x O y , including synthesis method, characterization of acid sites and acid strength, and applications.

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Section: Ar-tpdmentioning

confidence: 99%

Review of SO 2− 4 /M x O y solid superacid catalysts

Liao

2009

Front. Chem. Eng. China

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“…The nitrogen quadrupole moment can interact with the dipole of hydroxyl groups on silica surfaces, and argon has been suggested as a probe for acid sites on silaceous materials (Matsuhashi et al 2001). The good agreement obtained, between the fitted value of the nitrogen monolayer capacity for the homotattic patch model, and the corresponding values obtained independently by SAXS, mercury porosimetry, and butane BET, suggests that the structural/geometric component of the model is probably correct.…”

Section: Discussionmentioning

confidence: 75%

Fundamental studies of gas sorption within mesopores situated amidst an inter-connected, irregular network

et al. 2008

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There has been little, or no, direct testing of theories of gas sorption within particular pores situated amidst a highly inter-connected pore network. The concept of thermodynamically independent pores within networks has also been challenged. In this work, a novel integrated nitrogen sorption and mercury porosimetry technique has been used to deconvolve the condensation and evaporation processes within a specific subset of pores contained within a larger, irregular network. The sizes and geometry of these pores were obtained completely independently of gas sorption, using mercury porosimetry and NMR cryoporometry, respectively. Hence, various theories of capillary condensation, such as the Kelvin equation, the Broeckhoff-de Boer method, Saam-Cole theory, and NLDFT could be directly tested, and the potential influence of any collective network phenomena detected. It was found that, even for a shielded pore, the Cohan equation for a cylindrical meniscus gave rise to the best prediction for the relative pressure of capillary condensation, once the effects of surface chemical heterogeneity on multi-layer build-up had been taken into account. The results were also found to be incompatible with the presence of particular collective adsorption effects, such as advanced condensation.

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“…Ar was found to be applicable as a probe for the temperatureprogrammed desorption. The acid strength can be estimated by the activation energy of Ar desorption from solid acids [19] or by the adsorption heat of Ar [20].…”

Section: Resultsmentioning

confidence: 99%