In this work, we prepared the ordered nanoporous carbon replicas (CR) by templating method using organized nanoporous silica SBA-15 as a template. The prepared CR samples were chemically modified with H3PO4 concentrates in order to investigate the hydrogen storage behaviors. From the results, the H3PO4 treatments were proven to introduce oxygen-functional groups to carbon surfaces and change the textural properties of the samples. Moreover, the amount of hydrogen adsorption for H3PO4 treated samples was all enhanced except for the excessively treated sample (above 10 M H3PO4). Consequently, it could be concluded that hydrogen storage is greatly governed by the acidity of the carbon surfaces, resulting in enhancing electron acceptor–donor interactions at the interfaces (carbon surfaces-hydrogen molecules) due to the H3PO4 treatments.