What could be the reason for different behavior of phosphate tungsten and phosphate molybdenium bronzes in Briggs-Rauscher reaction: new insight

Abstract

Recently, two different effects of phosphate tungsten (PWB) and phosphate molybdenum (PMoB) bronzes (obtained by thermal treatment), on oscillatory Briggs-Rauscher (BR) dynamic have been found [1]. Although both are insoluble in BR solution [2], the addition of different masses of PWB linearly decreases the BR oscillation time, while the addition of different masses of PMoB had no effects on the BR reaction. Furthermore, PWB has an identical role as metal catalyst Mn2+ in BR reaction and for obtained behavior is probably responsible the different mechanisms of heterogeneous catalysis of these bronzes in oscillatory reaction. Therefore, a deeper investigation was done in order to find the major structural characteristic of these two bronzes by using the XRPD method. What is so different for these two bronzes, causing dissimilar effects in BR reaction, is it “just” catalytic activity of central cation or there is something more? The XRPD method confirmed very different structures of PWB and PMoB as monoclinic and orthorhombic, respectively [3,4]. This work tries to connect the structural properties of PWB and PMoB with BR oscillatory reaction responses, expanding the usage of oscillatory reaction in material science and catalysis, in general.