Hydrogen sorption properties of Pd-Co nanoalloys embedded into mesoporous carbons.

Pd90Co10 and Pd75Co25 nanoalloys embedded into mesoporous carbon hosts have been prepared by two synthetic methods: direct and indirect. The average nanoparticles size can be tuned by both the temperature during thermal treatment and the chemical composition: the higher the treatment temperature and the richer the Pd composition, the larger the nanoparticle size. Twofold size- and composition-dependence of the hydrogen sorption properties at room temperature are evidenced. The Co substitution in Pd nanoalloys increases the equilibrium pressure at room temperature relative to nanosized Pd. The hydrogen sorption capacity decreases by Co substitution in Pd, as also demonstrated by SQS + DFT calculations.