| 1 | The status of carbon neutrality of the world’s top 5 CO_(2) emitters as seen by carbon satellites显示文摘China,the Unite States(US),the European Union(EU),India,and Russia are the world’s top 5 fossil fuel and cement CO_(2)(FFC)emitting countries or regions(CRs).It is very important to understand their status of carbon neutrality,and to monitor their future changes of net carbon fluxes(NCFs).In this study,we implemented a well-established global carbon assimilation system(GCAS,Version 2)to infer global surface carbon fluxes from May 2009 to December 2019 using both GOSAT and OCO-2 XCO_(2)retrievals.The reductions of flux uncertainty and XCO_(2)bias,and the evaluation of posterior flux show that GCAS has comparable and good performance in the 5 CRs.The results suggest that Russia has achieved carbon neutrality,but the other 4 are still far from being carbon neutral,especially China.The mean annual NCFs in China,the US,the EU,India,and Russia are 2.33±0.29,0.82±0.20,0.42±0.16,0.50±0.12,and-0.33±0.23 PgC yr^(−1),respectively.From 2010 to 2019,the NCFs showed an increasing trend in the US and India,a slight downward trend after 2013 in China,and were stable in the EU.The changes of land sinks in China and the US might be the main reason for their trends.India’s trend was mainly due to the increase of FFC emission.The relative contributions of NCFs to the global land net carbon emission of China and the EU have decreased,while those of the US and India have increased,implying the US and India must take more active measures to control carbon emissions or increase their sinks.This study indicates that satellite XCO_(2)could be successfully used to monitor the changes of regional NCFs,which is of great significance for major countries to achieve greenhouse gas control goals. | Fei Jian Wei He Weimin Ju Hengmao Wang Mousong Wu Jun Wang Shuzhuang Feng Lingyu Zhang Jing MChen | 2022 | Fundamental Research2022，2，3： | 1 |
| 3 | Ru-based catalysts for efficient CO_(2) methanation:Synergistic catalysis between oxygen vacancies and basic sites显示文摘The fundamental insights of the reaction mechanism,especially the synergistic effect between oxygen vacancies and basic sites,are highly promising yet challenging for Ru-based catalysts during carbon dioxide(CO_(2))methanation.Herein,a series of Rubased catalysts were employed to study the mechanism of CO_(2) methanation.It is found that Ru/CeO_(2) catalyst exhibits a much higher CO_(2) conversion(86%)and CH4 selectivity(100%),as well as excellent stability of 30 h due to the existence of abundant oxygen vacancies and weak basic sites.Additionally,the in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and density functional theory(DFT)calculations reveal that the formate formation step dominated the hydrogenation route on Ru/CeO_(2) catalyst,and the b-HCOO^(*)could be the key intermediate due to b-HCOO^(*)is more easily hydrogenated to methane than m-HCOO^(*).The systematic study marks the significance of precise tailoring of the synergistic relationship between oxygen vacancies and basic sites for achieving the desired performance in CO_(2) methanation. | Chunfen Wang Yonglian Lu Yu Zhang Hui Fu Shuzhuang Sun Feng Li Zhiyao Duan Zhen Liu Chunfei Wu Youhe Wang Hongman Sun Zifeng Yan | 2023 | Nano Research2023，16，10： | 0 |
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