Unraveling the role of GaZrOx structure and oxygen vacancy in bifunctional catalyst for highly active and selective conversion of syngas into light olefins

•GaZrOx solid solution is prepared and mixed with SAPO-34 for syngas conversion.•Incorporation of Ga into ZrO2 enhanced the amounts of oxygen vacancy and OH group.•Strong synergetic effect of Zr and Ga promotes CO activation and H2 dissociation.•A high light olefin selectivity of 88.6% is achieved at CO conversion of 51.6%.•Matching temperature for CH3O* formation and transformation benefit the activity.