ZnCl2-activated S/N-doped biochar for low-temperature NH3-SCR of NOx: Performance and pathway analysis

Carbon-based catalysts for low-temperature denitrification were prepared from wheat straw via ZnCl2 activation and thiourea doping. The catalysts were systematically characterized using BET surface area analysis, NH3-TPD, XPS, and transient response experiments. The ZnCl2-activated catalyst exhibite...

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Bibliographic Details
Main Authors: Shuangshuang Yan, Dongmei Bi, Chengxizi Zhang, Zhisen He, Yu Ni, Kang Yue, Shanjian Liu
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:Green Energy and Resources
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Online Access:http://www.sciencedirect.com/science/article/pii/S2949720525000207
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Summary:Carbon-based catalysts for low-temperature denitrification were prepared from wheat straw via ZnCl2 activation and thiourea doping. The catalysts were systematically characterized using BET surface area analysis, NH3-TPD, XPS, and transient response experiments. The ZnCl2-activated catalyst exhibited a NOx reduction efficiency of 45.1%. To further enhance the denitrification performance, the Z1.2 biochar was co-doped with sulfur and nitrogen. Experimental results demonstrated that the SN2.5Z1.2/AC biochar catalyst achieved a maximum NO conversion of 88% within the temperature range of 50–260°C and exhibited stable activity in long-term durability tests. Sulfur and nitrogen co-doping markedly increased the number of strong acid sites and surface chemisorbed oxygen (Oα), thereby facilitating the formation of N-6 functional groups. The presence of C-SO3-H species may be a critical factor contributing to the enhanced NOx conversion. The denitrification process over sulfur- and nitrogen-doped biochar follows both the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms, wherein •NH2 radicals play a pivotal role in the reduction of NO to its gaseous and adsorbed forms.
ISSN:2949-7205