The effect of redox properties of the environment during synthesis on the structural and catalytic properties of ZrO2 in isobutane dehydrogenateion

[Display omitted] •ZrO2 catalyst for i-C4H10 dehydrogenation was obtained by laser vaporization.•The usage of a reducing atmosphere during synthesis significantly improves the activity of the ZrO2 catalyst.•A key characteristic of ZrO2 dehydrogenation catalysts is the number of oxygen vacancies. Recently, it was shown that ZrO2 catalysts, the activity of which is determined by the number of oxygen vacancies, are promising for dehydrogenation of light alkanes. In this study, environments with different redox properties were used to obtain a series of ZrO2 catalysts with different stoichiometric composition. To this end, samples of tetragonal ZrO2 with the particle size of 8–10 nm were synthesized by laser vaporization in an Ar and He atmosphere with the addition of H2 or O2. According to NH3-TPD data, the number of oxygen vacancies decreases in the series ZrO2 (He + H2) > ZrO2 (Ar + H2) > ZrO2 (He) > ZrO2 (Ar) ∼ ZrO2 (Ar + O2). The synthesized samples show high conversions of iso-C4H10 and selectivities to iso-C4H8. However, an increase in the number of oxygen vacancies in the samples leads to a less pronounced effect of the catalyst activation during the reaction. Thus, the highest conversion of 52 % and selectivity of 86 % were obtained for the ZrO2 (He + H2) sample, for which the activation was not observed at all. Therewith, the specific yield of isobutylene for the samples synthesized in hydrogen-containing atmospheres was higher compared to the samples obtained in oxidizing and inert atmospheres over the entire reaction time. Thus, the use of a reducing atmosphere during the synthesis is an efficient method for enhancing the catalytic performance of ZrO2 dehydrogenation catalysts. The results obtained indicate also that the catalytic performance of such catalysts is determined primarily by the number of oxygen vacancies rather than by reducibility of the oxide, which provides a new insight into the design of ZrO2 dehydrogenation catalysts.