太阳能驱动的二氧化碳和硫化氢协同转化的研究

The coexistences of carbon dioxide (CO2) and hydrogen sulfide (H2S) in natural gas have brought severe challenges for its exploitation, processing and application. Simultaneous conversion of CO2 and H2S gases into valuable products is an ideal strategy with economic and environmental benefits. In the present project, a solar-driven electrochemical process assisted by mediator is demonstrated for simultaneous conversion CO2 and H2S at near neutral conditions. Through the core research of developing the highly selective CO2 reduction catalysts, screening of mediator and coupling of photovoltaic electrochemical systems, we aim to simultaneously convert CO2 and H2S into methane and sulfur in analog natural gas. By means of electrochemical theory simulation, experimental verification and in-situ or semi-situ spectroscopy, the microscopic mechanism was studied for the conversion of CO2 and H2S. This conceptually provides an alternative avenue for the purification of natural gas with added economic and environmental benefits.

天然气中二氧化碳（CO2）和硫化氢（H2S）气体的存在对其开采、加工和利用带来严重的挑战，将CO2和H2S气体同时转化成有价值的产品是兼具经济和环境双重效益的理想策略。本项目将建立一种常温常压下媒介体辅助的光（电）化学同时资源化CO2和H2S的体系。通过开展高选择性CO2电还原催化剂的开发、捕获H2S媒介体的筛选和光伏电化学体系的耦合的研究，实现模拟天然气中CO2和H2S协同转化为甲烷和硫磺。借助电化学理论模拟、实验验证和原位或半原位的光谱等手段，研究CO2和H2S转化过程，获取整个过程所涉及的微观机理。将天然气中的CO2和H2S转化为高附加值化学品的理念为兼具环境和经济效益的天然气净化提供了一种新的思路。

天然气中二氧化碳（CO2）和硫化氢（H2S）气体的存在对其开采、加工和利用带来严重的挑战，将CO2和H2S气体同时转化成有价值的产品是兼具经济和环境双重效益的理想策略。本项目建立了一种常温常压下媒介体辅助的光（电）化学同时资源化CO2和H2S的体系，并搭建了相关装置。项目主要从三个方面开展了相关研究工作：1.媒介体筛选，通过大量的实验研究，最终获得了铁基媒介体。为解决铁离子穿透隔膜难题，我们提出络合剂策略和新隔膜策略。2.开发了金银团簇和多孔铜锡合金CO2电还原催化剂，获得了CO2还原产生一氧化碳和甲烷分别为98.4%和86.4%的法拉第效率，同时借助理论计算和原位电化学红外技术阐述了电催化CO2还原机制。3.提出光助液流电池策略，该策略能够将H2S持续稳定转化为硫磺和氢气，获得太阳能到化学能高达15.4%转化效率。相关研究成果以第一作者身份分别发表在 The Journal of Physical Chemistry Letters 和 ACS Energy Letters期刊上，授权国家发明专利一项。总之，项目负责人及团队顺利完成项目预定目标。该研究为天然气酸气处理提供了一条绿色路径。