Synthesis of Fine Chemicals by Heterogeneous Catalysis: A Critical Approach of the Role of Solvent for Hydrogenation Reactions

Liaison Functions
AIChE Annual Meeting
November 5, 2013 - 8:30am-9:00am

The synthesis of fine chemicals over solid catalysts often involves the use of solvents that may strongly influence the catalyst performance. Thus , the choice of suitable solvents is frequently critical to obtain high catalytic activity and selectivity. However , the optimal solvent selection requires a detailed knowledge on the relationship between the chemical nature of the solvents and the interactions taking place in the gas-liquid-solid catalytic systems. One of the most common types of catalytic reactions carried out in the presence of solvents is the hydrogenation of organic compounds. In particular , the selective hydrogenation of aromatic ketones into the corresponding alcohols on metal-based catalysts in the presence of different solvents has been widely studied. Here , the solvent effect on catalyst activity and selectivity for the liquid-phase hydrogenation of acetophenone to 1-phenylethanol was thoroughly investigated over Ni/SiO2. Solvents of different properties and polarities were used: i) protic solvents: methanol , ethanol , 1-propanol and 2-propanol; ii) aprotic polar solvents: acetonitrile , g-butyrolactone and tetrahydrofuran; iii) aprotic apolar solvents: cyclohexane , toluene and benzene. The relative interactions solvent–catalyst , solvent–reactant and reactant–catalyst and their influence on the activity pattern were considered in the analysis. Concerning the influence of the solvent-reactant interaction , classical polarity parameters (e.g. dipole moment m and dielectric constant ε) and other solvatochromic scales (e.g. hydrogen-bond donor (a) and hydrogen-bond acceptor (b) parameters , p* polarity/polarizability index , Kosower’s Z and ET(30) scales) were taken into account. The influence of H2 solubility in the solvents was also considered. For the solvent-catalyst and reactant-catalyst interactions , the corresponding molar adsorption enthalpies were measured calorimetrically and compared.

Professional Development Hours
0.5 PDHs
You will be able to download and print a certificate for these PDH credits once the content has been viewed. If you have already viewed this content, please click here to login.

Would you like to access this content?

No problem. You just have to complete the following steps.

You have completed 0 of 2 steps.

  1. Log in

    You must be logged in to view this content. Log in now.

  2. Purchase Technical Presentation

    You must purchase this technical presentation using one of the options below.
    If you already purchased this content recently, please click here to refresh the system's record of ownerships.


Credits 0.5 Use credits
List Price $99.00 Buy now
AIChE Members $69.00 Buy now
AIChE Undergraduate Student Members Free Free access
AIChE Graduate Student Members Free Free access
Related Topics: