21.

Overview of the coating materials using ALD on particulate materials for electrocatalytic applications. (a) The number of counts of each coating material reported in the literature, (b) Pie chart of the ALD coating materials for electrocatalysis applications. M: metal; MO: metal oxide; SA: single atom; MN: metal nitrides; BM: bimetallic catalyst, and (c) Pie chart depicting four major and some minor (others) electrochemical applications of ALD on particulate materials. PEMFCs: proton exchange membrane fuel cells, ORR: oxygen reduction reaction, HER: hydrogen evolution reaction, MOR: methanol oxidation reaction. The others include OER: oxygen evolution reaction, FAOR: formic acid oxidation reaction, SOFC: solid oxide fuel cells, GOR: glycerol oxidation reaction, AOR: alcohol oxidation reaction, HP: hydrogen pumping, and CO2RR: CO2 reduction reaction.