TY - JOUR

T1 - Stability and thermal behaviour of BH4-anions inside pores of sodium-potassium-tetrahydroborate aluminosilicate sodalite (Na1-x Kx)8[AlSiO4]6(BH4) 2; X ~ 0.5

AU - Matussek, Tanja

AU - Buhl, Josef Christian

PY - 2009/7/11

Y1 - 2009/7/11

N2 - Tetrahydroborate enclathrated sodalites are interesting compounds which offer new concepts for hydrogen storage as well as possibilities of special chemical reactions inside pores by the strong reduction force of tetrahydroborate. In the present paper, we show that these new materials can be further modified by hydrothermal cation exchange without decomposition of the predominant amounts of the hydrolysis sensitive BH4 - anions inside the sodalite cages. We succeeded in preparing sodalite (Na 1-x Kx)8[AlSiO4]6(BH 4)2; (x ∼ 0.5) by hydrothermal treatment of the pure sodium tetrahydroborate sodalite in KNO3-solution at 473 K for 48 h. This product was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and temperature dependent FT-IR-spectroscopy. Investigations of thermal reaction behaviour of the enclathrated BH4 - anions revealed a decrease in metaborate formation temperature close to 100 K compared with the pure sodium tetrahydroborate sodalite. This is discussed by structural changes according to potassium incorporation and the influence of degradation of crystallinity during cation exchange.

AB - Tetrahydroborate enclathrated sodalites are interesting compounds which offer new concepts for hydrogen storage as well as possibilities of special chemical reactions inside pores by the strong reduction force of tetrahydroborate. In the present paper, we show that these new materials can be further modified by hydrothermal cation exchange without decomposition of the predominant amounts of the hydrolysis sensitive BH4 - anions inside the sodalite cages. We succeeded in preparing sodalite (Na 1-x Kx)8[AlSiO4]6(BH 4)2; (x ∼ 0.5) by hydrothermal treatment of the pure sodium tetrahydroborate sodalite in KNO3-solution at 473 K for 48 h. This product was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX) and temperature dependent FT-IR-spectroscopy. Investigations of thermal reaction behaviour of the enclathrated BH4 - anions revealed a decrease in metaborate formation temperature close to 100 K compared with the pure sodium tetrahydroborate sodalite. This is discussed by structural changes according to potassium incorporation and the influence of degradation of crystallinity during cation exchange.

KW - Cation exchange

KW - Hydrogen storage

KW - Thermal properties

KW - Zeolites

UR - http://www.scopus.com/inward/record.url?scp=68449101585&partnerID=8YFLogxK

U2 - 10.1007/s11144-009-0028-y

DO - 10.1007/s11144-009-0028-y

M3 - Article

AN - SCOPUS:68449101585

VL - 97

SP - 281

EP - 288

JO - Reaction Kinetics and Catalysis Letters

JF - Reaction Kinetics and Catalysis Letters

SN - 0133-1736

IS - 2

ER -