FIELD OF THE INVENTION

The present invention relates to methods for the preparation of nitrogen- and/or oxygen-functionalized carbonaceous supports having metal nanoparticles disposed thereon. The present invention further relates to nitrogen- and/or oxygen-functionalized carbonaceous supports having metal nanoparticles disposed thereon and their use as heterogeneous catalysts.

BACKGROUND OF THE DISCLOSURE

Catalysts are used in a large number of applications including large-scale production of inorganic and organic chemicals, crude oil refining, environmental protection and remediation, and energy conversion. Among various catalysts, heterogeneous catalysts that are not soluble in reaction mixtures are advantageous due to benefits such as easy separation from reaction mixtures, recyclability and better handling properties, thus showing promising industrial value. As such, heterogeneous catalysts have been explored for years in the pursuit of materials to enable more environmentally friendly industrial processes.

Many industrial catalysts consist of metals or metal compounds supported on a heterogeneous support. The basic role of the heterogeneous support is to maintain the catalytically active phase (i.e., the metal of metal compound) in a highly dispersed state. However, in many instances the role of the support is not merely that of a carrier; it may also directly or indirectly contribute catalytic activity. In some instances, the interaction between the catalytically active phase and the support phase can synergistically affect the catalytic activity, where each of the support and the metal/metal compound have different catalytic capabilities.

Metal oxides such as, for example, Al2O3, SiO2, and TiO2, have been used as catalyst supports. However, the use of metal oxide supports is problematic due to dissolution of the supports under acidic or basic conditions. Carbonaceous materials, such as activated carbon (AC), carbon nanotubes (CNTs), and carbon nanofibers (CNFs), have shown to be excellent catalyst supports due to their chemical stability, high surface area and porosity, and adequate mechanical properties. However, the high cost and difficulties of large-scale production limit the application of CNTs and CNFs.

Despite the wealth of research devoted to heterogeneous catalysts to date, the search for more efficient and tunable heterogeneous catalysts, as well as more facile methods of making the same, persists in the field.

