Such a strategy can produce various robust SACs and cluster catalysts. Similarly, the confined space in non-collapse metal-organic frameworks prevents the excessive aggregation of Cu single atom under cathodic potentials, yielding ultrasmall nanoclusters (~ 4 nm) for a benchmark performance in ammonia electrosynthesis via nitrate reduction. Mimicking the homogeneous catalyst through a reversible opening and closing of the metalligand coordination sphere in the catalytic cycle is another emerging approach to achieving controllable dynamism. As shown in Reaction product-driven restructuring and assisted stabilization at the atomic scale during steam reforming of methane was also observed in the Rh-on-ceria catalyst. The introduction of such reversible coordination in heterogenous catalysis provides a new perspective for tuning the structural dynamism of SACs.