Morphology plays an important role in the physicochemical properties and catalytic activity of Co ₃ O ₄ catalysts.

Gaseous CO co-existence could improve catalytic toluene oxidation over Co₃O₄-based catalysts, and the reaction mechanism on the CO/toluene oxidation may be mutually independent in the presence of both CO and toluene.

The Pt–CeO₂ catalyst with adsorption sites and oxygen-rich vacancies exhibited outstanding activity towards CO and toluene co-oxidation.

Zinc oxide (ZnO), with the unique chemical and physical properties of high chemical stability, broad radiation absorption range, high electrochemical coupling coefficient, and high photo-stability, is an attractive multifunctional material which has promoted great interest in many fields. What is more, its properties can be tuned by controllable synthesized morphologies. Therefore, after the success of the abundant morphology controllable synthesis, both the morphology-dependent ZnO properties and their related applications have been extensively investigated. This review concentrates on the properties of morphology-dependent ZnO and their applications in catalysis, mainly involved reactions on green energy and environmental issues, such as CO₂ hydrogenation to fuels, methanol steam reforming to generate H₂, bio-diesel production, pollutant photo-degradation, etc. The impressive catalytic properties of ZnO are associated with morphology tuned specific microstructures, defects or abilities of electron transportation, etc. The main morphology-dependent promotion mechanisms are discussed and summarized.