Double catalytic activation using bifunctional

Double Catalytic Activation Using a Bifunctional Catalyst with Both Acid and Base on Solid Surfaces... 

Since the last decades, chemists have described a huge variety of multi-catalytic systems and cooperative effects [6]. First of all, it has been shown that cooperative effects can appear by combining two catalytic functions within the same molecule (bifunctional catalysis) [7] or in two separate molecules (cooperative dual catalysis) [8,9], Both can participate to the same catalytic cycle by activating together the same substrate (double-activation catalysis) or its own substrate. The two catalytic centers can also activate simultaneously different substrates in two directly coupled catalytic reactions for giving a product (synergistic catalysis) [10]. Tandem reactions have been also described [11, 12]. In that case, the two catalytic centers operate consecutively in two independent catalytic cycles, the second catalytic cycle using the product of the first one as an intermediate and converts it as final product. The second catalytic function may also not interact with the substrates but contributes to the stability of the active metal center and acts as redox partner (restorative catalysis) [8]. 

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