Chemical reaction and summarized references in Section 2.

Section	Reaction	Clusters	References
2.1.1	H2 evolution reaction	Pt	24 and 25
2.1.1	H2 evolution reaction	Pd	26 and 34
2.1.1	H2 evolution reaction	Au	27–34
2.1.2	O2 evolution reaction	Pd	26
2.1.2	O2 evolution reaction	Au	40 and 41
2.2	Electrocatalytic reaction for fuel cells	Pt	45–48 and 55
2.2	Electrocatalytic reaction for fuel cells	Au	49–54 and 56
2.3	Photocatalytic water splitting reaction	Pt	58 and 59
2.3	Photocatalytic water splitting reaction	Au	60–64, 67 and 68
2.3	Photocatalytic water splitting reaction	Ag	65 and 66
2.4	Redox reaction for solar cell	Au	69, 71 and 73–78
2.4	Redox reaction for solar cell	Ag	70 and 72–74
2.4	Redox reaction for solar cell	Pt	71
2.4	Redox reaction for solar cell	Pd	71