Enhanced Hydrogen Transport over Palladium Ultrathin Films through Surface Nanostructure Engineering.
Palladium ultrathin films (around 2 μm) with different surface nanostructures are characterized by TEM, SEM, AFM, and temperature programmed reduction (TPR), and evaluated in terms of H2 permeability and H2-N2 separation. A change in the characteristics of Pd seeds by controlled oxidation-reduction treatments produces films with the same thickness, but different surface and bulk nanostructure. In particular, the films have finer and more homogeneous Pd grains, which results in lower surface roughness. Although all samples show high permeo-selectivity to H2 , the samples with finer grains exhibit enhanced permeance and lower activation energy for H2 transport. The analysis of the data suggests that grain boundaries between the Pd grains at the surface favor H2 transfer from surface to subsurface. Thus, the surface nanostructure plays a relevant role in enhancing the transport of H2 over the Pd ultrathin film, which is an important aspect to develop improved membranes that function at low temperatures and toward new integrated process architectures in H2 and syngas production with enhanced sustainability.
Dept. DIECII, Section Industrial Chemistry, University of Messina, ERIC aisbl and INSTM/CASPE, V.le F. Stagno D'Alcontres 31, 98166, Messina, Italy.
Salvatore
http://orcid.org/0000-0001-6935-7372
S
Abate
Dept. DIECII, Section Industrial Chemistry, University of Messina, ERIC aisbl and INSTM/CASPE, V.le F. Stagno D'Alcontres 31, 98166, Messina, Italy.
Gianfranco
G
Giorgianni
Dept. DIECII, Section Industrial Chemistry, University of Messina, ERIC aisbl and INSTM/CASPE, V.le F. Stagno D'Alcontres 31, 98166, Messina, Italy.
Serena
S
Gentiluomo
Dept. DIECII, Section Industrial Chemistry, University of Messina, ERIC aisbl and INSTM/CASPE, V.le F. Stagno D'Alcontres 31, 98166, Messina, Italy. centi@unime.it.
Gabriele
http://orcid.org/0000-0001-5626-9840
G
Centi
Dept. DIECII, Section Industrial Chemistry, University of Messina, ERIC aisbl and INSTM/CASPE, V.le F. Stagno D'Alcontres 31, 98166, Messina, Italy.
Siglinda
http://orcid.org/0000-0001-8814-1972
S
Perathoner
D004738:Engineering; D006859:Hydrogen / Q000737:chemistry*; D049329:Nanostructures / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D010084:Oxidation-Reduction; D010165:Palladium / Q000737:chemistry*; D010539:Permeability; D013499:Surface Properties
D010165:Palladium; D006859:Hydrogen; D009584:Nitrogen
grain size; hydrogen transport; nanostructure; palladium; ultrathin film