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Surface properties of Ca, Ti‐doped CeO 2 and their influence on the reverse water‐gas shift reaction
Author(s) -
Mordekovitz Yuval,
Shelly Lee,
Rosen Brian A.,
Hayun Shmuel
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17623
Subject(s) - adsorption , ionic radius , dopant , catalysis , water vapor , doping , inorganic chemistry , chemical engineering , materials science , water gas shift reaction , chemistry , ion , organic chemistry , optoelectronics , engineering
CeO 2 ‐based materials can be found in a variety of catalytic processes, including the reverse water‐gas shift (RWGS) reaction. Nevertheless, the interaction of molecular gases with the surfaces of such materials is still not clear. Recently, some progress was reported on the incorporation of neodymium (Nd) and calcium (Ca) into ceria and their effect on H 2 O and CO 2 adsorption. Titanium (Ti), which has a much smaller ionic radius, has the ability to change the interaction landscape, both as a co‐dopant to Ca and as a sole dopant in the CeO 2 system. In this study, the interactions of environmental gases (i.e., water vapor and CO 2 ) on the surface of Ti‐doped CeO 2 and Ca,Ti co‐doped CeO 2 were investigated. Ti addition to CeO 2 was shown to decrease water vapor uptake by up to 25% all while maintaining similar heats of adsorption. In the case of CO 2 adsorption, Ti addition to CeO 2 had lowered the uptake by more than 50% as well as lowering the heat of adsorption. Co‐doping with Ti and Ca showed small decrease in H 2 O uptake accompanied with increased heat of adsorption. For CO 2 , the changes to the uptake and energetics were small and did not indicate a specific trend. The RWGS catalytic performance showed improvement by the addition of Ti in certain levels. The relationship between the doping, surface properties, gas‐surface interactions, and catalytic performance is discussed.