Sodium nitrate modified SBA-15 and fumed silica for efficient production of acrylic acid and 2,3-pentanedione from lactic acid

The catalytic conversion of lactic acid to acrylic acid and 2,3-pentanedione over sodium nitrate-supported mesoporous SBA-15 and fumed silica was studied. The yields of acrylic acid, 2,3-pentanedione, and acetaldehyde are 44.8%, 25.1%, and 13.3%, respectively, over the 23%NaNO₃/SBA-15 catalyst. The performance of the catalysts is strongly affected by NaNO₃ loading, catalyst texture and porosity, and product diffusion efficiency. A proper control of NaNO₃ loading can result in modification catalyst structure for improvement of 2,3-pentanedione selectivity. Under certain reaction conditions, the surface NaNO₃ species can readily transform to sodium lactate that functions as active component to catalyze the target reactions.