Direct conversion of methane (CH4) to methanol (DMTM) is a promising, but very challenging process for the utilization of abundant CH4 as a low carbon resource. In this context, Cu loaded zeolites, mordenite (MOR) in particular, were recognized as the most effective system to perform DMTM. In this work, different Cu salts were used to exchange with MOR, by which the effect of counter ions on the catalytic performance towards DMTM was investigated. The prepared catalysts were characterized and evaluated systematically. It was found that the counter ions affected the speciation of Cu sites, probably due to their capability in extraction of protons from MOR and the influence on the hydrolysis state of the Cu2+ in aqueous solution. These behaviors adjusted the association between Cu2+and the exchangeable protons in MOR. As a result, varied DMTM performance was observed. Among the used Cu salts, Cu(CH3COO)2 exchanged MOR showed the highest performance, achieving stable CH3OH yield of 117 ± 28μmol/g in 5 consecutive cycles, these values are among the highest for Cu loaded MOR zeolites in open publications. ? 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.