Non-toxic catalysts include a variety of materials such as enzymes, zeolites, and certain metal oxides. For instance, enzymes are biologically derived catalysts that are biodegradable and generally non-toxic. Zeolites are microporous, aluminosilicate minerals that act as catalysts in petrochemical industries and are considered environmentally benign. Metal oxides like titanium dioxide are also used as non-toxic catalysts in photocatalytic processes.
