Strategy (Hydrogenation catalysts)

Catalytic hydrogenation is one of the most popular reactions in industrial applications. As often used in various catalytic reactions, gaseous hydrogen is one major optional reagent among other hydrogen sources mostly because of its stability. Controllable variables, such as catalyst, reaction temperature, reaction pressure or mixing, enables gaseous hydrogen be active or inactive at a certain reaction condition.   

The usual difficulty in catalytic hydrogenation mostly comes out when partial hydrogenation is needed and further reaction needs to stop to produce saturated products, in other words to induce higher selectivity. This requires more of specific catalytic performance than of reactive atomic hydrogen sources. Understanding activation energy differences helps be more theoretical.  

This activation energy also relates with the strength of adsorption. The higher adsorption strength, the easier the dissociation of hydrogen or dissociation of any other chemical bonds takes place.  

In practice, what catalyst we need to use is totally up to the reaction conditions. Variations of catalytic performances in Pd, Pt or Ni catalysts seem somewhat less important at early stage of the research. However, if we are targeting at fine chemicals, variations of any characteristics can determine the whole viability of the process. 

 

Let me be more specific on each topic I mentioned above although some of the explanations are quite controversial.

1) Hydrogen stability 

2) Adsorption 

3) Dissociation of bonds 

4) Activation energy 

5) Characteristics of metal catalyst 

6) Reaction selectivity