Quest for a structure-property relationship in sulfonated graphene catalysts for the additive esterification of carboxylic acids and olefins

We report the catalytic property of sulfonated reduced graphene oxide (SO₃H-rGO) in the context of the additive esterification between carboxylic acids and olefins. The acid concentration in SO₃H-rGO can be modified during preparation, the SO₃H-rGO-5 at the optimal concentration of 2.66 mmol/g exhibits the highest catalytic activity in the additive reaction between acetic acid and isobutylene. The SO₃H-rGO can exhibit better catalytic activity than two benchmark porous catalysts such as sulfonated activated carbons (SO₃H-AC) and sulfonated SBA-15 (SO₃H-SBA). Specifically, the superior performance of SO₃H-SrGO observed for substrates with large steric hindrance (camphene and acrylic acid) suggests that its 2D sheet-like nanostructure can circumvent the mass transfer issue presented in conventional porous heterogeneous catalysts.