Light olefins (C2-C4 olefins) are the most important basic carbon-based building blocks, which are mainly produced from the catalytic cracking of naphtha [1-3].With the rapid depletion of oil reserves and the growing demand for lower olefins, there is an urgent need to develop an alternative technique for producing them from non-petroleum resources such as coal, natural gas, or biomass.Currently, coal has been successfully transformed to olefins in China via the combination of the processes of coal-to-syngas, syngas-to-methanol and methanol-to-olefins [4-6].In order to further improve efficiency and reduce investment, the direct conversion of syngas to olefins has received extensive attention in recent years [7].