Metallic Cu is a well-known electrocatalyst for nitrate reduction reaction (NO 3 RR), but it suffers from relatively low activity, poor stability, and inducing nitrite accumulation during the long-term operation. Herein, it is found that Cu catalysts minimized at the single-atom level can overcome the limitations of bulk materials in NO 3 RR. A metal-nitrogen-carbon (M-N-C) electrocatalyst composed of carbon nanosheets embedding isolated copper atoms coordinated with N, Cu-N-C-800, is synthesized by pyrolysis of a Cu-based metal-organic framework at 800 °C. In comparison with Cu nanoparticles and Cu plate-800, kinetic measurements show that the Cu-N-C-800 electrocatalyst is more active and stable and distinctly suppresses the release of nitrite intermediate into the solution. The combined results of experimental data and density functional theory calculations indicate that Cu bound with N (particularly Cu-N 2) is the key to favorable adsorption of NO 3 − and NO 2 −. This strong binding is responsible for the enhanced rate of nitrate conversion to the end products of ammonia and nitrogen. These findings highlight the promise of single-atom Cu electrocatalysts for nitrate reduction with desirable performance.

Background Coronary heart disease (CHD) has become a leading cause of morbidity and premature death worldwide. Cardiac rehabilitation (CR) was proved to have substantial benefits for patients with CHD. The CR was divided into three phases. Phase 2 is the important part of CR which involves hospital-based structured and closely monitored exercises and activities. However, CR utilization is low worldwide. The barriers to hospital-based phase 2 CR in China have not been well identified. Aims To investigate barriers to hospital-based phase 2 cardiac rehabilitation among coronary heart disease patients in China and to explore the reasons. Methods This study employed an explanatory sequential mixed-methods design. The study was conducted in a university hospital in China from July 2021 to December 2021. Quantitative data was collected through the Cardiac Rehabilitation Barrier Scale. Qualitative data was collected through unstructured face-to-face interviews. Data analysis included descriptive statistics and inductive qualitative content analysis. Results One hundred and sixty patients completed the Cardiac Rehabilitation Barrier Scale and 17 patients participated in unstructured face-to-face interviews. The main barriers identified were distance (3.29 ± 1.565), transportation (2.99 ± 1.503), cost (2.76 ± 1.425), doing exercise at home (2.69 ± 1.509) and time constraints (2.48 ± 1.496). Six themes were identified; logistical factors, social support, misunderstanding of cardiac rehabilitation, program and health system-level factors, impression of CR team and psychological distress. The first four themes confirmed the quantitative results and provide a deeper explanation for the quantitative results. The last two themes were new information that emerged in the qualitative phase. Conclusion This study provides a better understanding of the barriers to hospital-based phase 2 cardiac rehabilitation among coronary heart disease patients in the Chinese context during the Covid-19 pandemic. Innovative programs such as home-based CR, mobile health, and hybrid programs might be considered to overcome some of these barriers. In addition, psychosocial intervention should be included in these programs to mitigate some of the barriers associated with the impression of CR team and psychological distress.

In article number 2004526, Chunhua Feng and co‐workers demonstrate that Cu catalysts minimized at the single‐atom level can overcome the limitations of nanoparticles and bulk materials in nitrate reduction reaction (NO3RR). These catalysts anchored on nitrogenated carbon nanosheets exhibit outstanding activity and stability for NO3RR and distinctly suppress the release of nitrite intermediate due to the favorable adsorption of NO3− and NO2−.