Nickel Single Atom Density-Dependent CO Efficient Electroreduction.

The transition metal-nitrogen-carbon (M─N─C) with MNx sites has shown great potential in CO electroreduction (CORR) for producing high value-added C products. However, a comprehensive and profound understanding of the intrinsic relationship between the density of metal single atoms and the CORR performance is still lacking. Herein, a series of Ni single-atom catalysts is deliberately designed and prepared, anchored on layered N-doped graphene-like carbon (x Ni@NG-900, where x represents the Ni loading, 900 refers to the temperature).

Effects of intermetal distance on the electrochemistry-induced surface coverage of M-N-C dual-atom catalysts.

The often-overlooked electrocatalytic bridge-site poisoning of the emerging dual-atom catalysts (DACs) has aroused broad concerns very recently. Herein, based on surface Pourbaix analysis, we identified a significant change in the electrochemistry-induced surface coverages of DACs upon changing the intermetal distance. We found a pronounced effect of the intermetal distance on the electrochemical potential window and the type of pre-covered adsorbate, suggesting an interesting avenue to tune the electrocatalytic function of DACs.

Surface states of dual-atom catalysts should be considered for analysis of electrocatalytic activity.

Experimentally well-characterized dual-atom catalysts (DACs), where two adjacent metal atoms are stably anchored on carbon defects, have shown some clear advantages in electrocatalysis compared to conventional catalysts and emerging single-atom catalysts. However, most previous theoretical studies directly used a pristine dual-atom site to analyze the electrocatalytic activity of a DAC. Herein, by analyzing 8 homonuclear and 64 heteronuclear DACs structures with ab initio calculations, our derived surface Pourbaix diagrams show that the surface states of DACs generally differ from a pristine surface at electrocatalytic operating conditions.

Comparative clinical studies of primary chemoradiotherapy versus S-1 and nedaplatin chemotherapy against stage IVb oesophageal squamous cell carcinoma: a multicentre open-label randomised controlled trial.

Introduction: Oesophageal squamous cell carcinoma (OSCC) is one of the most commonly occurring devastating tumours worldwide, including in China. To date, the standard care of patients with stage IV OSCC is systemic chemotherapy and palliative care, which results in poor prognosis. However, no consensus has been established regarding the role of radiotherapy in targeting the primary tumour in patients with stage IVa OSCC.