Linear Relationship of the Rate of Isobutene Formation from CO and H2 on ZrO2 to the Monoclinic Phase Fraction

The rate of formation of isobutene from CO and H2 over ZrO2 is proportional to the volume fraction of the monoclinic phase. The active site was explained by both vacant site and stronger bascity due to the shorter Zr-O bond in the monoclinic structure.