Hcl acs reagent

Pd nanocubes were prepared through
a hydrothermal synthesis route
by modifying a previously reported method.^{18 (link)} Dihydrogen tetrachloropalladate (H₂PdCl₄,
10 mM) was prepared from 10 mM PdCl₂ (99.9%, Sigma–Aldrich)
and 20 mM HCl (ACS reagent, 37%, Sigma–Aldrich) and reduced
by l-ascorbic acid (99%, Alfa Aesar) under the presence of
hexacetyltrimethylammonium bromide (CTAB, >99%, Sigma–Aldrich)
at 95 °C. After 25 min, the solution was centrifuged, washed
two times with 1:1 ethanol/water, and dispersed in ultrapure water
(resistance = 18.2 MΩ). The SnO₂@Pd NCs were prepared
by following the same method and with further addition of 5 at. %
SnSO₄ (>95%, Sigma–Aldrich) 15 min after the
start
of the reaction. The NCs were supported on carbon by adding carbon
Vulcan XC72R powder to the nanocubes’ aqueous dispersion and
sonicating the suspension thoroughly. The ligands were removed by
adding 0.25 M NaOH. After complete precipitation, the samples were
washed thoroughly with ultrapure water and dried at 105 °C overnight.
The catalyst inks with a concentration of 4 mg/mL were prepared
by sonicating the carbon-supported NCs in isopropanol for 5 min. From
this, a 10-μL aliquot, corresponding to 40 μg of catalyst,
was pipetted onto a glassy carbon substrate and dried in air.