Mesoporous SBA-15 was synthesized and modified with 3-chloropropyltrimethoxysilane and then used in immobilization of creatinine groups, which were employed to introduce Y3+ and Ce3+ to give rise to two novel yttrium and cerium catalysts: SBA-15@Creatinine@M (M = Y and Ce). The structures of the SBA-15@Creatinine@M catalysts were determined using various techniques. These catalysts offered outstanding catalytic performances in the oxidation of sulfides to sulfoxides and in the preparation of 5-substituted 1H-tetrazoles. An important characteristic of the SBA-15@Creatinine@M catalysts is that they are very stable without a considerable decrease in their catalytic performance lasting seven cycles.