A Spontaneous Hydrogen Fuel Purifier under Truly Ambient Weather Conditions

Abstract

Hydrogen economy is an ideal energy vector to offer a carbon-neutral energy pathway. However, the contamination of produced hydrogen with carbonaceous and non-carbonaceous impurities beyond the tolerance level of a fuel cell, always demands exceptionally endergonic fuel separation modules requiring multiple-steps and extreme temperatures and pressures (- 85°C to -15°C and 7 to 30 bar). These contribute to serious energy imbalance between the key-steps of hydrogen production and hydrogen utilization. By directly harvesting the water-formation energy, we show spontaneous fuel purification under truly ambient weather conditions including open-air environment, wherein contaminated hydrogen streams can be purified to nearly 99.9 % purity in a single-step at the expenditure of ∼24 kJ/molH2 with an electrical energy output of ∼90 kJ/molH2. As a major leap in hydrogen economy, a laboratory-level prototype can spontaneously generate ∼99.4 % pure hydrogen in a single-step even from a quaternary mixture of impurities including hydrocarbons, CO2 and N2.