In many reactions restricted by water, selective removal of water from the reaction system is critical and usually requires a membrane reactor. We found that a simple physical mixture of hydrophobic poly(divinylbenzene) with cobalt-manganese carbide could modulate a local environment of catalysts for rapidly shipping water product in syngas conversion. We were able to shift the water-sorption equilibrium on the catalyst surface, leading to a greater proportion of free surface that in turn raised the rate of syngas conversion by nearly a factor of 2. The carbon monoxide conversion reached 63.5%, and 71.4% of the hydrocarbon products were light olefins at 250°C, outperforming poly(divinylbenzene)-free catalyst under equivalent reaction conditions. The physically mixed CoMn carbide/poly(divinylbenzene) catalyst was durable in the continuous test for 120 hours. Channeling water away Heterogeneous catalytic reactions that produce water as a by-product can be inhibited by its presence on the surface. Fang et al . found that for the production of light olefins from syngas (a 2:1 mixture of hydrogen and carbon monoxide) with a cobalt manganese carbide catalyst at 250°C, the addition of the hydrophobic polymer polydivinylbenzene as part of a physical mixture almost doubled the conversion of carbon monoxide (see the Perspective by Ding and Xu). Theoretical models suggest that the polymer formed channels that accelerated water diffusion away from the catalyst. —PDS Mixing a hydrophobic polymer with a solid catalyst improves performance by accelerating the escape of product water.