Modification　of　Ru/CeO2　catalysts　for　ammonia　synthesis　from　H2　and　N2　is　of　emerging　interest　for　potential　industrial　application.　Herein,　we　report　an　effective　strategy　by　introduction　silica　to　enhance　ammonia　synthesis　performance　by　tuning　hydrogen　adsorption-desorption　property.　Owing　to　the　enhancement　of　Ru　sites　surrounded　by　oxygen　atoms,　ceria-supported　Ru　catalyst　with　SiO2　adsorbs　more　hydrogen　species,　and　the　desorption　and　exchange　of　hydrogen　species　would　also　be　accelerated.　Therefore,　the　introduction　of　SiO2　into　Ru/CeO2　catalyst　can　improve　the　ammonia　synthesis　activity　by　more　than　34%　at　400　°C,　and　the　catalyst　with　SiO2　shows　a　lower　activation　energy　and　superior　high-pressure　effect　for　ammonia　synthesis.　These　findings　will　open　up　a　new　avenue　for　the　development　of　ammonia　synthesis　and　also　provide　guidance　for　preparing　highly　efficient　oxides-supported　metal　catalysts　in　a　series　of　hydrogen-involving　reactions.　©　2022　Elsevier　Ltd