Hydrogen sorption by porous materials composed of one to three elements selected from boron, carbon and nitrogen and metal modification to enhance the sorption

•Nanocarbons, BN’s and CN’s were successfully prepared through wet processes.•Their hydrogen capacity at 77K and 0.8MPa exceeded 2.34 mass% per 1,000 m2 g-1.•While Pd-modification did not enhance hydrogen sorption, Pt-modification substantially did.•Ni increased hydrogen capacity of nanocarbons originated from electrospun polyacrylonitrile. In order to develop novel hydrogen storage materials with high hydrogen capacity, layered compounds with high specific surface areas and large pore volumes, referred to as BN’s, CN’s and C’s, were synthesized from B-, C- and/or N-containing substances through specified wet processing and optimized calcinations. Hydrogen contents at 77K under 0.8MPa of hydrogen increased as specific surface areas increased independently of the formulations of the samples, and almost all of them exceeded the predicted values for two dimensional condensation of hydrogen, that is, 2.34mass% per 1000m2g−1. While modification with Pd did not increase the hydrogen capacity, Pt-modification brought about substantially higher hydrogen capacity at 77K. Ni-modification also imparted higher hydrogen capacity to C’s prepared by calcination of electrospun polyacrylonitrile fibers, but formation of mesopores on destroying micropores through excessive modification would reduce the hydrogen capacity.