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The emerging atomic‐level synergistic catalysts based on the single‐atom sites and other valuable components, such as atom, cluster, nanoparticle and other nano‐matter, shine in various catalytic fields. They can integrate the advantages of individual catalytic sites and other valuable components to enhance the activity, selectivity and stability of many chemical reactions via activating their key rate‐determining steps and multistep transformations. In addition, because of the ultrahigh atom utilization (~100 %) and adjustable microenvironment of metal centers, the single‐atom sites can intelligently construct with other useful large size sites to strengthening in tandem a typical catalytic process. Herein, the structure and mechanism of atomic‐level synergistic catalysts with controllable electronic structures and regulatory reaction processes are presented. We particularly emphasize the interactions between active components of atomic‐level synergistic catalysts and catalytic reaction processes, which are essential for understanding how these catalysts are cooperatively working. It is anticipated that this minireview can make the promotion of advanced atomic‐level synergistic catalysts based on single‐atom sites. [ABSTRACT FROM AUTHOR]

Aims/Background Backward walking is gaining traction in rehabilitation therapy, showing promise as an intervention for stroke patients with walking difficulties. However, the brain activity patterns (neurophysiological mechanisms) underlying backward walking in these patients remain unclear. This study investigated the neurophysiological mechanism in stroke patients within 1 year of their stroke. Methods Twenty-four subjects walked forward and backward for 5 min on an 8-m track while their electroencephalographic signals were collected. The power values of each frequency band were compared during forward and backward walking, and the delta to alpha power ratio (DAR) was calculated. Results The results showed a significant increase in α-band activity within the frontal cortex during backward walking (p < 0.05). This increase correlated positively with scores on the Fugl-Meyer lower extremity motor function assessment scale. Similarly, α-band activity showed significant enhancement within the right parietal cortex during backward walking (p < 0.05). There were no significant differences between forward and backward walking states in δ, θ, and β wavebands across the entire brain region (p > 0.05). Additionally, the DAR was significantly lower during backward walking than during forward walking (p < 0.05). Conclusion This study suggests that backward walking may more effectively activate neural activity in the prefrontal and right posterior parietal cortices. This finding supports the potential of backward walking to enhance motor execution and walking function in stroke patients, thereby supporting its application as a rehabilitation method. [ABSTRACT FROM AUTHOR]

Owing to the inertness of CO2 molecules, the development of highly active photocatalysts for CO2 reduction reactions (CO2RR) remains a formidable challenge. Here, we designed an MXene-based single-atom Fe co-catalyst (Fe1/Ti3−xC2Ty) featuring fast Ti–Fe electron channels to achieve enhanced CO2RR performance. The synthesized Fe1/Ti3−xC2Ty exhibited a CO yield of 259.0 μmol g−1 h−1 without the addition of any organic sacrificial agents. The experimental and computational results reveal that, electrons transfer from Ti to Fe and then accumulate at the active sites, which facilitates the transfer of charges and enhances the activation of CO2 molecules. This work provides a new direction of MXene-based non-noble-metal monoatomic catalysts for efficient photoreduction of CO2 under gas–solid photocatalytic conditions with pure water. [ABSTRACT FROM AUTHOR]

The rational design of efficient bifunctional single-atom electrocatalysts for industrial water splitting and the comprehensive understanding of its complex catalytic mechanisms remain challenging. Here, we report a Ni single atoms supported on oxygen-incorporated Mo2C via Ni-O-Mo bridge bonds, that gives high oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) bifunctional activity. By ex situ synchrotron X-ray absorption spectroscopy and electron microscopy, we found that after HER, the coordination number and bond lengths of Ni-O and Ni-Mo (Ni-O-Mo) were all altered, yet the Ni species still remain atomically dispersed. In contrast, after OER, the atomically dispersed Ni were agglomerated into very small clusters with new Ni-Ni (Ni-O-Ni) bonds appeared. Combining experimental results and DFT calculations, we infer the oxidation degree of Mo2C and the configuration of single-atom Ni are both vital for HER or OER. This study provides both a feasible strategy and model to rational design highly efficient electrocatalysts for water electrolysis. The comprehensive understanding of complex catalytic mechanisms under harsh reaction conditions for efficient bifunctional single-atom electrocatalysts remain challenging. Here the authors found microenvironment reconsitution of highly active Ni single atoms on oxygen-incorporated Mo2C for water splitting. [ABSTRACT FROM AUTHOR]

Cu single-atom catalysts (Cu SACs) have been considered as promising catalysts for efficient electrocatalytic CO 2 reduction reactions (ECRRs). However, the reports on Cu SACs with an asymmetric atomic interface to obtain CO are few. Herein, we rationally designed two Cu SACs with different asymmetric atomic interfaces to explore their catalytic performance. The catalyst of CuN 3 O/C delivers high ECRR selectivity with an FE CO value of above 90% in a wide potential window from -0.5 to -0.9 V vs RHE (in particular, 96% at -0.8 V), while CuCO 3 /C delivers poor selectivity for CO production with a maximum FE CO value of only 20.0% at -0.5 V vs RHE. Besides, CuN 3 O/C exhibited a large turnover frequency (TOF) up to 2782.6 h -1 at -0.9 V vs RHE, which is much better than the maximum 4.8 h -1 of CuCO 3 /C. Density functional theory (DFT) results demonstrate that the CuN 3 O site needs a lower Gibbs free energy than CuCO 3 in the rate-determining step of CO desorption, leading to the outstanding performance of CuN 3 O/C on the process of ECRR-to-CO. This work provides an efficient strategy to improve the selectivity and activity of the ECRR via regulating asymmetric atomic interfaces of SACs by adjusting the coordination atoms.