Heterogeneous Catalysts for the Guerbet Coupling of Alcohols

Alcohol coupling, also known as the Guerbet reaction, is a potentially important process to increase the value of short chain alcohols. Metal oxides, metal phosphates, and supported transition metals, such as copper, are important components of heterogeneous catalysts for the reaction. However, the wide variety of catalyst compositions, reaction conditions, and reactor configurations used to study the reaction complicate a direct comparison of various catalysts. In this review, rates over different catalysts will be compared, the influences of the acid and base properties of the catalyst on product selectivity will be presented, and possible reaction paths to accomplish alcohol coupling will be discussed.