Fabrication of −SO3H functionalized aromatic carbon microspheres directly from waste Camellia oleifera shells and their application on heterogeneous acid catalysis

Sulfonic acid groups functionalized aromatic carbon microspheres (Ar-CMSs–SO 3 H) were first successfully fabricated directly from waste Camellia oleifera shells by simple steps in the assistance of phloroglucinol . As a heterogeneous solid Brønsted acid catalyst, the as-prepared Ar-CMSs–SO 3 H showed considerably high activity because of its numerous spherical microstructure and abundant surface sulfonic acid groups (–SO 3 H). Subsequently, the as-prepared Ar-CMSs–SO 3 H was applied to the synthesis of biofuels 5-ethoxymethylfurfural (EMF) from biological platform compounds 5-hydroxymethylfurfural (HMF). The catalytic results showed that both sulfonation conditions in the course of Ar-CMSs–SO 3 H preparation and catalytic reaction conditions in the course of EMF synthesis had a significant effect on the EMF yield and HMF conversion rate.