Carbon-based solid acids: a review

Green chemistry has fostered research on recyclable, insoluble and easily separable heterogeneous catalysts. Carbon materials are widely used for renewable energy and environmental studies. Here, we review the synthesis, properties and applications of carbon solid acids in the form of biomass, polymers, and carbon/silica-based catalysts. We show in particular that mesoporosity has a major role in catalysis, notably when bulk materials are transformed into valuable products.