Catalytic potential of the wonderful chameleons: Nickel phosphate molecular sieves

This review is devoted to the discoveries and knowledge developed in the past 10-15 years in the area of the design and applications of nickel phosphate molecular sieves (VSB-1 and VSB-5). The main textural and physicochemical characteristics of these materials that make them suitable for catalysis were viewed at the molecular and atomic levels. According to various spectroscopic investigations, the type of metal ions introduced into the VSB-1 and VSB-5 framework allows one to adjust the nature of the surface functional groups and thereby, affects the catalytic properties. Emphasis is placed upon the relationship between the physicochemical properties and their catalytic properties in hydrogenation, oxidation and acid-base type reactions. Because of the simultaneous existence of acid-base and red-ox pairs, nickel phosphate molecular sieves, similar to a chameleon, can adapt to catalytic systems and provide necessary active sites. This review clearly demonstrates that nickel phosphate molecular sieves (VSB-n series) possess promising catalytic properties: e.g., shape selectivity, red-ox and acid-base catalysis, and we expect that this work opens the door to novel applications of these materials in catalysis.