TY - JOUR
T1 - Thermochemistry of formation of ion exchanged zeolite RHO
AU - Guo, Xin
AU - Wu, Lili
AU - Corbin, David R.
AU - Navrotsky, Alexandra
N1 - Funding Information:
The authors are grateful to Pinghui Zhang for helpful discussions. DRC is grateful to Drs. Mark Shiflett, Bill Gilbert and David Minnick at the Center for Environmentally Beneficial Catalysis at the University of Kansas for their assistance in sample selection. This work was supported by the U.S. Department of Energy , Office of Science , grant DE-SC0016573 .
Publisher Copyright:
© 2018 Elsevier Inc.
PY - 2019/1/15
Y1 - 2019/1/15
N2 - Zeolites Na,Cs-RHO, Cd,Cs-RHO, and Li,NH4-RHO were synthesized in an aqueous ion-exchange media and studied by powder X-ray diffraction. Their thermochemistry was investigated by differential scanning calorimetry and high temperature oxide melt solution calorimetry. The formation enthalpy from binary oxide components of hydrated zeolite RHO varies linearly with the average ionic potential (Z/r) of the extra-framework cations and ranges from −34.46 ± 0.52 kJ/mol for Na,Cs-RHO to −16.75 ± 0.57 kJ/mol for Cd,Cs-RHO. The formation enthalpies for dehydrated zeolite RHO range from −25.49 ± 0.64 kJ/mol for Na,Cs-RHO to +4.12 ± 0.99 kJ/mol for Li,NH4-RHO. These values do not vary linearly with average ionic potential but do show a linear relationship with distortion parameter.
AB - Zeolites Na,Cs-RHO, Cd,Cs-RHO, and Li,NH4-RHO were synthesized in an aqueous ion-exchange media and studied by powder X-ray diffraction. Their thermochemistry was investigated by differential scanning calorimetry and high temperature oxide melt solution calorimetry. The formation enthalpy from binary oxide components of hydrated zeolite RHO varies linearly with the average ionic potential (Z/r) of the extra-framework cations and ranges from −34.46 ± 0.52 kJ/mol for Na,Cs-RHO to −16.75 ± 0.57 kJ/mol for Cd,Cs-RHO. The formation enthalpies for dehydrated zeolite RHO range from −25.49 ± 0.64 kJ/mol for Na,Cs-RHO to +4.12 ± 0.99 kJ/mol for Li,NH4-RHO. These values do not vary linearly with average ionic potential but do show a linear relationship with distortion parameter.
KW - Formation enthalpy
KW - Hydrated and dehydrated zeolite RHO
KW - Ionic potential
KW - Pore size
KW - Structural distortion parameter
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U2 - 10.1016/j.micromeso.2018.09.003
DO - 10.1016/j.micromeso.2018.09.003
M3 - Article
AN - SCOPUS:85053464881
VL - 274
SP - 373
EP - 378
JO - Microporous Materials
JF - Microporous Materials
SN - 1387-1811
ER -