10.1016/j.nanoen.2014.10.008
Formic acid-reduced ultrasmall Pd nanocrystals on graphene to provide superior electocatalytic activity and stability toward formic acid oxidation

The graphene oxide (GO) was synthesized from graphite by using a modified Hummers method [20] and [21]. The prepared graphene oxide was dried in normal vacuum at 70 degC for 12 h and then put into a glass bottle under high vacuum level at 60 degC overnight, followed by heating to 220 degC quickly. 

In a typical synthesis of Pd@Graphene electrocatalyst (30% Pd), graphene 10.5 mg, poly(vinyl pyrrolidone) (PVP) 40 mg, and (NH4)2PdCl4 12 mg were dissolved in 2 mL of deionized water. The mixture was treated in an ultrasonic bath to form a uniform aqueous dispersion, then added 3 mL HCOOH and ultrasonically treated for 10 min. The obtained black power was isolated by centrifugation, cleaned by three cycles of centrifugation/washing, and oven-dried at 60 degC for more than 6 h.
graphene oxide
dried
70 degC
degC
graphene oxide
dried
12 h
h
graphene oxide
high vacuum level
60 degC
degC
graphene oxide
heating
220 degC
degC
Pd
30%
%
graphene
dissolved
10.5 mg
mg
poly(vinyl pyrrolidone) (PVP)
dissolved
40 mg
mg
(NH4)2PdCl4
dissolved
12 mg
mg
deionized water
2 mL
mL
HCOOH
added
3 mL
mL
uniform aqueous dispersion, then added 3 mL HCOOH
ultrasonically treated
10 min
min
obtained black power
oven-dried
60 degC
degC
obtained black power
oven-dried
more than 6 h
h