Question

You are asked to design a catalyst for hydrogenation of alkenes. The catalyst is to be prepared with mixed metal (4% Pd and 1% Pt) on a suitable support. Considering the nature of a hydrogenation reaction and the phase in which the reaction is to take place, answer the following questions:

(a) What support material would you recommend and why?

(b) What should be the physical form of the support?

(c) What should be the desirable mechanical and thermal property of the support material?

(d) What is the role of Pt in the mixed metal?

(e) What would be the recommended loading method of the mixed metals on your chosen support material?

(f) What would be your recommendation for dispersion of the mixed metal on the support material - Eggshell, Intermediate or Uniform dispersion? Explain your choice for the method of dispersion.

(g) What temperature would you recommend to activate the catalyst in-situ?

Answer 1

(a) Carbon would be the support material.

(b) Solid form

(c) Desirable mechanical and thermal property of the support materials are:

- Inertness to the process

- High surface area

- Stable in reaction and regeneration processes

- Attrition resistance hardness

- It should have compressive strength

- It should have low cost

(d) Role of Pt is the hydrogenation of alkenes.

(e) Incipient wetness impregnation is an effective method

(f) Uniform dispersion, since uniform dispersion allows more surface area of the catalyst to be exposed to the reactants and facilitates higher conversions.

(g) Temperature should be in the range of 250 - 300 ^oC.