Recent studies have reported peculiar observations of superior gas enclathration in impurified ice compared to pristine ice. For example, McLaurin et al. observed a rapid and complete methane hydrate formation in methanol-doped ice with methanol dosages from 0.6 to 10 wt% under conditions of 12.5 MPa and 253 K (Fig ). McLaurin et al. also observed a similar promotion of methane enclathration in ammonia-doped ice with ammonia dosages from 0.3 to 2.7 wt% (Fig ). Overall, the rate of gas enclathration in the doped ice was two orders of magnitude higher than that obtained for pristine ice. Likewise, Amtawong et al. indicated that a trace amount of methanol in ice with a methanol fraction of around 100 ppm remarkedly accelerated the propane enclathration in comparison with the case without dopants. Nguyent et al. reported that doping perchloric acid (HClO 4 ) in THF hydrates with a dosage of one HClO 4 molecule per 136 water molecules resulted in a twofold increase in the diffusion coefficient of H 2 in the mixed THF-H 2 hydrates. These studies demonstrated the favourable gas enclathration in doped ices. In a different way, Chen et al. reported that doping ethanol in the gas phase also resulted in the promotion of methane enclathration into ice powder. Under conditions of ~16.5 MPa and temperatures ranging from 258 to 272 K, ethanol in methane gas with ethanol dosages up to 94 ppm by mole led to a phenomenal increase in the methane uptake. The ice-to-hydrate conversion increased from 15% in experiments using ordinary methane gas to 80 % in those using ethanol-doped methane gas (Fig ) The dopant-induced promotion of gas enclathration presents an intriguing phenomenon. Dopants such as methanol, ethanol, ammonia and HClO 4 are antifreezers and known as thermodynamic inhibitors of gas hydrate formation. Methanol is widely used to inhibit gas hydrate formation in oil and gas pipelines, which otherwise creates pipeline plugging and operation interruptions. Given the well-known inhibiting effects of antifreezers on gas hydrate formation, the observed acceleration of gas hydrate formation upon doping these additives presents a puzzling finding. To our knowledge, there have been no plausible rationales for such unexpected effects of underdosed antifreezers on gas enclathration.