P-doped carbon nanotube and Ge-doped boron nitride nanotube as a real catalysts for N2OÂ +Â SiO reaction: DFT examination

The mechanisms of N2O reduction via SiO on surfaces of P-doped carbon nanotube (CNT) and Si-doped boron nitride nanotube (BNNT) by density functional theory were investigated. The P and Si adsorption energies on surfaces of CNT and BNNT were calculated to be −314.6 and −347.2 kcal/mol, respectively. The decomposition of CNT-P-N2O and BNNT-Ge-N2O and reduction of CNT-P-O* and BNNT-Ge-O* by SiO molecule were investigated. The BNNT-Ge-O* has lower activation energy and more negative ΔGad rather than CNT-P-O* and therefore the process of BNNT-Ge-O* + SiO → BNNT-Ge + SiO2 was spontaneous more than CNT-P-O* + SiO → CNT-P + SiO2 from thermodynamic view point. Results show that activation energy for BNNT-Ge-O* + N2O → BNNT-Ge-O2 + N2 and CNT-P-O* + N2O → CNT-P-O2 + N2 reactions were 27.89 and 31.56 kcal/mol, respectively. The results show that P-doped CNT and Ge-doped BNNT can be observed as a real catalyst for the reduction of N2O.