In this article, we report the results of careful, room-temperature, high-pressure adsorption studies, in which simple complexes of copper and silver reversibly adsorb hydrogen when dispersed within nanoporous carbon. Whereas these complexes alone did not adsorb hydrogen, when they were nanoconfined within carbon, they adsorbed 1−3 mol of H 2 per metal center. As a figure of merit, nanoconfined cupric formate adsorbed ∼2.6 H 2 /Cu at 100 bar and 20 °C, much larger than any reported metal-containing adsorption medium. On carbon alone, the heat of hydrogen adsorption decreased with an increase in adsorption extent, limiting to insufficient levels of uptake. By contrast, when these metal salts were dispersed within the carbon, the heats of adsorption increased markedly in a linear manner, meaning that the thermodynamics has moved in the right direction and is not self-limiting. Such thermodynamic behavior is associated with side-on dihydrogen binding onto a metal center, the so-called Kubas binding. Such interaction, however, is generally observed with earlier transition metals and is therefore rather unexpected with coinage metals. Thus, we infer that there are cooperative interactions between hydrogen, the carbon pore, and the metal center, which may be exploited to enhance reversible hydrogen adsorption and to reach more practical levels.