Synthesis of PdO‐ZnO mixed oxide precursors for PdZn intermetallic catalysts

Abstract

PdZn mixed oxides are precursors for the formation of intermetallic PdZn phases, which show improved catalytic performance for methanol steam reforming. In this work we have prepared mixed oxides (Pd x Zn 1-x O) that span a range of compositions around the tetragonal PdZn 1:1 L 10 phase (x = 0.25, 0.5 and 0.75). We find that Pd +2 can be isomorphously substituted into hexagonal ZnO and likewise Zn +2 can also be substituted within tetragonal PdO. Our results show that the mixed oxide has a composition Pd 0.75 Zn 0.25 O within the tetragonal PdO lattice with a slight contraction in unit cell volume. The results are relevant for understanding the enhanced sensing properties of ZnO and the nature of the oxide precursors for the synthesis of intermetallic PdZn nanoparticles for heterogeneous catalysis.

Proving a Paradigm in Methanol Steam Reforming: Catalytically Highly Selective InxPdy/In2O3 Interfaces

“…(a) TEM micrograph of the as-prepared aerogel, revealing a network structure consisting of polycrystalline secondary particles. (b) XRD pattern of the as-prepared aerogel with the calculated patterns of In 2 O 3 , PdO, Pd In­(OH) 3 , and InO­(OH) . (c) TGA/MS measurement of the as-prepared Pd/In 2 O 3 aerogel along with the ion current for the fragments m / z = 18 as an indicator for water and m / z = 44 as an indicator for CO 2 .…”

Mesoporous zinc platinate and platinum nanotubes: insights into the formation mechanism and their catalytic activity

“…ZnO is a versatile template to synthesize novel material nanostructures with hollow interiors due to the ease of etching of ZnO in an acidic medium or reducing atmosphere. 67,[70][71][72][73][74][75][76] In our work, porous platinum nanotubes are synthesized by the microwave-induced reaction between chloroplatinic acid and ZnO nanorods in an aqueous medium. The dual role of ZnO nanorods as sacrificial templates and as morphology-directing agents guides the formation of porous nanotubes during the microwave reaction.…”

Properties of Bulk In‐Pt Intermetallic Compounds in Methanol Steam Reforming

“…Among the different intermetallic catalytic materials for MSR, ZnPd is the most intensively investigated one. [9,10,[16][17][18][19][20][21][22][23] Its high CO 2 -selectivity is ascribed to the formation of ZnO patches on ZnPd particles, while a clean ZnPd surface was shown to be unselective towards CO 2 . [16,17] The discrimination between the catalytic properties of ZnPd and a ZnPd/ZnO interface was achieved by determining the intrinsic catalytic properties of unsupported bulk ZnPd.…”

“…Among the different intermetallic catalytic materials for MSR, ZnPd is the most intensively investigated one [9,10,16–23] . Its high CO 2 ‐selectivity is ascribed to the formation of ZnO patches on ZnPd particles, while a clean ZnPd surface was shown to be unselective towards CO 2 [16,17] .…”