One-step direct production of methanol from methane and water(PMMW)under mild conditions is challenging in heterogeneous catalysis owing to the absence of highly effective catalysts.Herein,we designed a series of“Sin...One-step direct production of methanol from methane and water(PMMW)under mild conditions is challenging in heterogeneous catalysis owing to the absence of highly effective catalysts.Herein,we designed a series of“Single-Atom”-“Frustrated Lewis Pair”(SA-FLP)dual active sites for the direct PMMW via density functional theory(DFT)calculations combined with a machine learning(ML)approach.The results indicate that the nine designed SA-FLP catalysts are capable of efficiently activate CH4 and H_(2)O and facilitate the coupling of OH^(*)and CH_(3)^(*)into methanol.The DFT-based microkinetic simulation(MKM)results indicate that CH_(3)OH production on Co1-FLP and Pt1-FLP catalysts can reach the turnover frequencies(TOFs)of 1.01×10^(−3)s^(-1)and 8.80×10^(−4)s^(-1),respectively,which exceed the experimentally reported values by three orders of magnitude.ML results unveil that the gradient boosted regression model with 13 simple features could give satisfactory predictions for the TOFs of CH_(3)OH production with RMSE and R^(2)of 0.009 s^(-1)and 1.00,respectively.The ML-predicted MKM results indicate that four catalysts including V_(1-),Fe_(1-),Ti_(1-),and Mn_(1)-FLP exhibit higher TOFs of CH_(3)OH production than the value that the most relevant experiments reported,indicating that the four catalysts are also promising catalysts for the PMMW.This study not only develops a simple and efficient approach for design and screening SA-FLP catalysts but also provides mechanistic insights into the direct PMMW.展开更多
常规的碳捕集与封存技术和碳捕集、利用与封存技术多针对固定源排放CO_(2),直接空气捕集CO_(2)(Direct Air Capture,DAC)技术作为一种新兴的负碳排放技术可对分布源排放的CO_(2)进行捕集,进一步降低全球大气CO_(2)体积分数。介绍了DAC...常规的碳捕集与封存技术和碳捕集、利用与封存技术多针对固定源排放CO_(2),直接空气捕集CO_(2)(Direct Air Capture,DAC)技术作为一种新兴的负碳排放技术可对分布源排放的CO_(2)进行捕集,进一步降低全球大气CO_(2)体积分数。介绍了DAC典型液体吸收工艺、固体吸附工艺的发展过程及相关示范项目建设情况,分析了新兴DAC工艺的技术特点,探讨了现有DAC工艺关键装置方案和未来发展趋势。DAC液体吸收工艺具有吸收剂原料成本较低、选择性较高的特点,可实现大规模连续化捕集,但再生过程中能耗较高。DAC固体吸附工艺具有模块化、投资成本较低的特点,且再生过程能耗相对较低,但需要定期对吸附材料更换和吸附设备维护,适用于较小规模的DAC应用场景。对2种典型DAC工艺吸收/吸附材料进行了概述。DAC电振荡吸附工艺中CO_(2)在固体电极中发生化学反应被捕集,并通过外加电场改变固体电极极性实现CO_(2)脱附,该工艺具有比基于热量或压力的分离过程更高的效率。空气中CO_(2)选择透过DAC分离膜从而实现了高效碳捕集。DAC变湿吸附工艺通过湿度的改变实现CO_(2)的吸脱附,突破了常规变温/变压吸附的高能耗限制等问题。DAC生物吸收工艺通过藻类生物的光合作用将CO_(2)吸收固定。基于双功能催化剂的DAC工艺可以在一个综合过程中实现CO_(2)的捕集与催化,节省了CO_(2)捕集后的运输与存储成本。DAC液体吸收工艺的关键装置为空气接触器、颗粒反应器、煅烧炉和熟化器,其中空气接触器开发的核心在于提高气液接触效率,减少喷淋过程中的水分损失和减轻设备腐蚀,颗粒反应器和熟化器开发的关键在于提高固液两相物料的接触效率以及反应后的固液分离效率。DAC固体吸附工艺由引风模块、吸附/再生模块、供能再生模块和CO_(2)压缩模块组成的模块化装置组成,其中优化吸附模块的核心在于提高气固传质速率、调谐CO_(2)捕集效率、降低压降;并基于不同应用场景工艺需求选择合适的再生系统或利用清洁能源,优化DAC工艺过程和开发高性能的DAC核心装置至关重要。展开更多
文摘One-step direct production of methanol from methane and water(PMMW)under mild conditions is challenging in heterogeneous catalysis owing to the absence of highly effective catalysts.Herein,we designed a series of“Single-Atom”-“Frustrated Lewis Pair”(SA-FLP)dual active sites for the direct PMMW via density functional theory(DFT)calculations combined with a machine learning(ML)approach.The results indicate that the nine designed SA-FLP catalysts are capable of efficiently activate CH4 and H_(2)O and facilitate the coupling of OH^(*)and CH_(3)^(*)into methanol.The DFT-based microkinetic simulation(MKM)results indicate that CH_(3)OH production on Co1-FLP and Pt1-FLP catalysts can reach the turnover frequencies(TOFs)of 1.01×10^(−3)s^(-1)and 8.80×10^(−4)s^(-1),respectively,which exceed the experimentally reported values by three orders of magnitude.ML results unveil that the gradient boosted regression model with 13 simple features could give satisfactory predictions for the TOFs of CH_(3)OH production with RMSE and R^(2)of 0.009 s^(-1)and 1.00,respectively.The ML-predicted MKM results indicate that four catalysts including V_(1-),Fe_(1-),Ti_(1-),and Mn_(1)-FLP exhibit higher TOFs of CH_(3)OH production than the value that the most relevant experiments reported,indicating that the four catalysts are also promising catalysts for the PMMW.This study not only develops a simple and efficient approach for design and screening SA-FLP catalysts but also provides mechanistic insights into the direct PMMW.
文摘常规的碳捕集与封存技术和碳捕集、利用与封存技术多针对固定源排放CO_(2),直接空气捕集CO_(2)(Direct Air Capture,DAC)技术作为一种新兴的负碳排放技术可对分布源排放的CO_(2)进行捕集,进一步降低全球大气CO_(2)体积分数。介绍了DAC典型液体吸收工艺、固体吸附工艺的发展过程及相关示范项目建设情况,分析了新兴DAC工艺的技术特点,探讨了现有DAC工艺关键装置方案和未来发展趋势。DAC液体吸收工艺具有吸收剂原料成本较低、选择性较高的特点,可实现大规模连续化捕集,但再生过程中能耗较高。DAC固体吸附工艺具有模块化、投资成本较低的特点,且再生过程能耗相对较低,但需要定期对吸附材料更换和吸附设备维护,适用于较小规模的DAC应用场景。对2种典型DAC工艺吸收/吸附材料进行了概述。DAC电振荡吸附工艺中CO_(2)在固体电极中发生化学反应被捕集,并通过外加电场改变固体电极极性实现CO_(2)脱附,该工艺具有比基于热量或压力的分离过程更高的效率。空气中CO_(2)选择透过DAC分离膜从而实现了高效碳捕集。DAC变湿吸附工艺通过湿度的改变实现CO_(2)的吸脱附,突破了常规变温/变压吸附的高能耗限制等问题。DAC生物吸收工艺通过藻类生物的光合作用将CO_(2)吸收固定。基于双功能催化剂的DAC工艺可以在一个综合过程中实现CO_(2)的捕集与催化,节省了CO_(2)捕集后的运输与存储成本。DAC液体吸收工艺的关键装置为空气接触器、颗粒反应器、煅烧炉和熟化器,其中空气接触器开发的核心在于提高气液接触效率,减少喷淋过程中的水分损失和减轻设备腐蚀,颗粒反应器和熟化器开发的关键在于提高固液两相物料的接触效率以及反应后的固液分离效率。DAC固体吸附工艺由引风模块、吸附/再生模块、供能再生模块和CO_(2)压缩模块组成的模块化装置组成,其中优化吸附模块的核心在于提高气固传质速率、调谐CO_(2)捕集效率、降低压降;并基于不同应用场景工艺需求选择合适的再生系统或利用清洁能源,优化DAC工艺过程和开发高性能的DAC核心装置至关重要。
基金supported by the National Natural Science Foundation of China(No.22038011,No.22078257,No.22108213,No.52176142)the China Postdoctoral Science Foundation(2021M692548)+1 种基金the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy(Grant YLU-DNL Fund 2022001)the Young Talent Support Plan of Shaanxi Province。
