近期，金属单原子催化剂已成研究热点，但尚待深入：（1）此类催化剂表面能巨大，液相中或高温时易团聚；（2）可能不适合多原子协同反应的催化。该申请项目拟开展基于银原子与银离子(Agnδ+,2 ≤ n ≤ 4)共混超小团簇的研究，特点：（1）该团簇自身带有电荷，通过团簇间静电排斥可有效防止团聚，有利于本项目后续研究；（2）相关的超小团簇，在尺度上仍接近单个原子（可称为准单原子），催化效率仍很高；（3）相关的超小团簇有可能实施多原子协同反应的催化。研究内容主要包括：首先采用模板加控制性还原的方法制备关键性产物(Agnδ+,2 ≤ n ≤ 4)；继而研究它与过渡金属氧化物（MxOy）的负载问题，包括二次还原成电中性原子簇(Agn,2 ≤ n ≤ 4)，光催化活性及理论计算，同时关注Ag超小团簇的孤立、聚集、自组装等状态下表面等离子效应（SPR）的强弱、光吸收位置等问题。

Most recently, atomically dispersed catalysts have attracted rapidly increasing attention, especially for noble metals, due to their unique catalytic properties and highest atom efficiency. However, this research also faces the challenges from (1) Aggregation of single metal atoms (SMA) in liquid phase or through sintering,resulting from large special surface area of SMA. (2) Possibly, being against to concerted catalysis of ultiple atoms. So herein we suggest an improved method based on ultrafine cluster consisted of Ag(0) and Ag(I) (Agnδ+,2 ≤ n ≤ 4), which shows advantages as follows: (1)The positive charge of ultrafine cluster can protect their aggregation effectively. (2)This ultrafine cluster is closed to SMA in size, called quasi SMA. (3) There is a high possibility to carry out the concerted catalysis of multiple atoms. Our research project including: The ultrafine clusters (Agnδ+,2 ≤ n ≤ 4) will be prepared by both template and controllable reduction reaction, and then obtained products as precursor will be loaded on the surface of transitional metal oxides(MxOy), carrying out further investigations including second reduction reaction for generation of Ag(0) ultrafine cluster, photocatalysis and theoretical simulation. In addition, it should be concerned that the surface plasmon resonance (SPR) from independent, aggregation or self-assembly of Ag(0) ultrafine cluster, which might result in change of strength and position of light absorption.