Unveiling the interfacial dynamics of Si/Al adsorption on calcium carbide: mechanistic insights and advanced applications

Abstract

The calcium carbide (CaC₂) acetylene industry, a cornerstone of coal chemistry, faces critical challenges in purity due to ash adhesion during high-temperature synthesis, in which silicon and aluminum dominate contamination. To unravel the relationship between atomic-level adsorption mechanism and the applications, the crystal structures, density functional theory (DFT) calculations, and the adsorption experiments have been analyzed. DFT calculations reveal distinct charge transfer behaviors: the atomic populations of Si and Al are 0.11e and 0.25e, respectively, with partial density of states and charge difference density analyses confirming stronger electron donation from Al to CaC₂, thereby rationalizing its preferential adsorption. HRTEM of reacted samples is used to directly visualize the lattice and spacing both of Al₂O₃ and CaC₂. By bridging orbital hybridization with macroscopic performance, strategies for high-purity carbide synthesis and acetylene processes are unlocked. The quantified correlation between electronic description and functional application underscores the transformative potential of sustainable energy systems.