Efficient nitric oxide capture and reduction on Ni-loaded CHA zeolites  

作　　者：Bin Yue Jianhua Wang Shanshan Liu Guangjun Wu Bin Qin Landong Li 

机构地区：[1]School of Materials Science and Engineering,Nankai University,Tianjin,300350,China [2]College of Chemistry,Nankai University,Tianjin,300071,China

出　　处：《Green Energy & Environment》2024年第12期1857-1865,共9页绿色能源与环境（英文版）

基　　金：supported by the National Natural Science Foundation of China(22302100,22025203,22121005);the Fundamental Research Funds for the Central Universities(Nankai University).

摘　　要：As a prominent contributor to air pollution,nitric oxide(NO)has emerged as a critical agent causing detrimental environmental and health ramifications.To mitigate emissions and facilitate downstream utilization,adsorption-based techniques offer a compelling approach for direct NO capture from both stationary and mobile sources.In this study,a comprehensive exploration of NO capture under oxygen-lean and oxygenrich conditions was conducted,employing Ni ion-exchanged chabazite(CHA-type)zeolites as the adsorbents.Remarkably,Ni/Na-CHA zeolites,with Ni loadings ranging from 3 to 4 wt%,demonstrate remarkable dynamic uptake capacities and exhibit exceptional NO capture efficiencies(NO-to-Ni ratio)for both oxygen-lean(0.17-0.31 mmol/g,0.32-0.43 of NO/Ni)and oxygen-rich(1.64-1.18 mmol/g)under ambient conditions.An NH3 reduction methodology was designed for the regeneration of absorbents at a relatively low temperature of 673 K.Comprehensive insights into the NO_(x) adsorption mechanism were obtained through temperature-programmed desorption experiments,in situ Fourier transform infrared spectroscopy,and density functional theory calculations.It is unveiled that NO and NO_(2) exhibit propensity to coordinate with Ni^(2+) via N-terminal or O-terminal,yielding thermally stable complexes and metastable species,respectively,while the low-temperature desorption substances are generated in close proximity to Na^(+).This study not only offers micro-level perspectives but imparts crucial insights for the advancement of capture and reduction technologies utilizing precious-metal-free materials.

关 键 词：Nitrogen oxides CAPTURE ZEOLITE Lean/rich condition Adsorption mechanism 

分 类 号：TQ424[化学工程] X701[环境科学与工程—环境工程]