“…In the presence of O 2 , however, another type of catalyst may be even more efficient. Velu et al [27,31,36], who studied the SRM reaction with addition of O 2 , found that ZrO 2 -containing Cu/ZnO/Al 2 O 3 catalysts are best suited for production of H 2 with ultralow CO levels. In the present study, the catalyst compositions were chosen in accordance with the findings in Refs.…”