Zeolite beta-filled chitosan membrane with low methanol permeability for direct methanol fuel cell

Abstract

a b s t r a c tZeolite beta particles with different sizes and narrow size distribution were hydrothermally synthesized and incorporated into chitosan (CS) matrix to prepare CS/zeolite beta hybrid membranes for direct methanol fuel cell (DMFC). It was found that the chitosan membrane filled by zeolite beta particles about 800 nm in size exhibited the lowest methanol permeability, which can be ascribed to their optimum free volume and methanol diffusion characteristics. To further improve the performances of CS/zeolite beta hybrid membranes, zeolite beta particles about 800 nm in size were sulfonated via three different approaches. The results indicated that the introduction of sulfonic groups could reduce the methanol permeability further as a result of the enhanced interfacial interaction between zeolite beta and chitosan matrix. Furthermore, in terms of the overall selectivity index, CS/zeolite beta hybrid membranes were comparable to Nafion ® 117 membrane at low methanol concentration (2 mol L −1 ) and much better at high methanol concentration (12 mol L −1 ).

Surface modification of mordenite in Nafion composite membrane for direct ethanol fuel cell and its characterizations: Effect of types of silane coupling agent

“…Similar behavior for FT-IR of the MPTS-treated zeolite data was reported elsewhere [44]. Nevertheless, the peak of the sulfonic acid group that appeared at 1,000-1,200 cm -1 did not appear in the MOR-MPTS spectra because they were overlapped by the peak of TO4 (Si, Al tetrahedral units) [5,38]. This was also the case for the spectra of…”

“…The separation of MOR particles might be due to the fact that the sizes of the particles were rather large. This was a limitation of the grinding [5,14,15,38,49]. Grinding in a fluid energy mill which is commonly used in the pharmaceutical and cosmetic industries may provide very fine-size products.…”

“…As a result, the performance of the fuel cell is decreased [4]. In the report of Wang et al [5], the selectivity values of chitosan and a Nafion ® 117 membrane were 1.49×10 4 and 1.71×10 4 Ss/cm 3 , respectively. In the report of Maab and Nunes [6], the permeability of ethanol for Nafion 117 was 5 times higher than a plain SPEEK membrane.…”

“…It was found that using zeolite beta can decrease the methanol permeability when compared with a pure chitosan membrane [5]. Yilser et al [18] prepared the Nafion/zeolite composite membrane with different zeolite loading for a low humidity proton exchange membrane fuel cell (PEMFC).…”

Organic/Inorganic Nanocomposite Membranes Development for Low Temperature Fuel Cell Applications

“…The cell performance of the composite membrane were comparable to Nafion ® 117 at low methanol concentration (2M) and much better at high methanol concentration (12M) (Y. Wang et al, 2008). Other zeolite based nanocomposite membranes investigated are MCM-41 (Bello et al, 2008;Gomes et al, 2008;Karthikeyan et al, 2005;Marschall et al, 2007), zeolite Y (Ahmad et al, 2006), zeolite BEA (Holmberg et al, 2005) and Chabazite and clinoptilolite (Tricoli & Nannetti, 2003).…”