Controlling residual metal in carbide-derived carbons for acid gas removal

Abstract

Carbide-derived carbons (CDC) contain a porous network of uniform pore sizes created through the removal of the metal heteroatoms and the reorganization of the remaining carbon. A key advantage of CDCs is that the metal for active sorption sites is already a part of the original carbide; consequently, incorporating metal sites can be accomplished via a one-pot synthesis procedure. Therefore, an understanding of the etching process is necessary to control the residual metal properties. Specifically, this work focuses on the effects of reactor design on particle properties. Titanium carbide is an ideal candidate to develop a fundamental understanding of the reactor design effects as titanium does not induce any changes in the carbon structure and follows a core-shell model of metal extraction. Additionally, testing manganese carbide allows for further understanding of how specific metal chlorides remain within their corresponding CDC frameworks as nanoparticles. Lastly, the adsorption properties of TiC-CDC with various amounts of residual metal are evaluated for carbon dioxide removal before and after exposure to acidic environments. The overall goal of this Ph.D. research is to uncover the fundamental knowledge that underpins CDC synthesis techniques and mechanisms to allow for the targeted design of CDCs for adsorptive interactions with acid gases. This goal will be achieved by completing the following objectives: 1. Develop novel techniques to control residual metal content in CDCs, 2. Control the etching mechanism to form metal nanoparticles from the carbide’s residual metal, and 3. Examine the impact of acidic environments on CDC features.