The adsorption behavior of BCl3SiHCl3 on aliphatic amine by DFT method

Abstract Background The removal of trace amount of BCl 3 from SiHCl 3 by adsorption is an efficient method in manufacture of electronic grade polysilicon. Objective DFT simulations were used to investigate the adsorption mechanism of aliphatic amine adsorbents and to compare the performance of these adsorbents. Methods The adsorption energies, mulliken charges, dipole moments and FMOs of aliphatic amines on SiHCl 3 and BCl 3 were calculated using the DFT method at the B3LYP/6‐311++G (2d, p) level, and on this basis the factors affecting the adsorption capacity and selectivity were explored in depth. Results The results indicates that these adsorbents show good adsorption performance and high separation efficiency for BCl 3 . In particular, (CH 3 ) 2 NH has the highest adsorption capacity for BCl 3 at 298 K and 1 atm and achieves effective desorption at high temperatures to allow the adsorbent to be reused. Conclusions The adsorption behaviors are strongly affected by frontier orbitals, dipoles and polarizabilities of aliphatic amines, among which HOMO of amines plays the decisive role for adsorbing BCl 3 , providing theoretical guidance for adsorbent design associated with removal of BCl 3 from SiHCl 3 .