The production of biodiesel from renewable resources has attracted much attention due to the increasing demand for energy.[1] One of the most important routes for producing biodiesel involves the transesterification of triglycerides with short-chain alcohols, normally catalyzed by acids and bases.[2–3] Liquid acids (eg, H2SO4) exhibit good catalytic activities but their environmentally unfriendly properties, such as strong corrosion and difficult ...