all chemicals and reagents used were of analytical grade. All of them
are of high-purity grade. Pinewood (Lowe’s), nickel(II) nitrate
hexahydrate (99%) (Acros Organics), ferric nitrate nonahydrate (98.6%)
(Fisher Scientific), cobalt(II, III) oxide (99.7%) (Alfa Aesar), and
molybdenum powder (99.9%) (Alfa Aesar) were purchased. After all of
the reagents were received, no further purification was required.
Tedler Gas bags (Thermo Scientific) (1 L) were used for sample injection
for the Micro Gas Chromatograph (Inficon Inc.). Deionized water was
used for the preparation of all aqueous solutions.