Correlating the chemical composition and size of various metal oxide substrates with the catalytic activity and stability of as-deposited Pt nanoparticles for the methanol oxidation reaction

Abstract

Enhanced Pt catalysis with metal oxide substrates.

Nanoscale Perovskites as Catalysts and Supports for Direct Methanol Fuel Cells

“…This analysisw as conducted with respectt ob oth SRO and SrTiO 3 (STO). [53] To this end, we prepared two distinctive size distributions of each metal oxide. Specifically,i ns eparatee xperiments, STO NPs with average diameters of 40.7 and 113.0 nm (Figure3A, E) weres ynthesized by using ah ydrothermal protocol and ap recipitation-calcination method, respectively.I np arallel, we prepared SRO NPs ( Figure 3C, G), possessing two different sizes (i.e.,3 7.3 and 146 nm), by co-precipitation reactions;t hese samples differed mainly with respect to altered annealing temperatures.…”

“…In summary,p erovskite-type metal oxides with various sizes were prepared, and our resultss howed that chemicalcomposition as opposed to size maybethe more significanta nd reliable indicator of electrochemical behavior.T hat is, thoughs ize is relevant, the identity of the B-site atom (i.e., Ti and Ru, in this case) itself was ab etter predictoro ft he MOR activity. [53],w ith permission from The RoyalS ocietyofC hemistry. [53] Chem.E ur.J.2019, 25,7779 -7797 www.chemeurj.org As discussed earlier,m etal oxides can act either as co-catalysts or as supports that give rise to beneficial metal-support interactions with their overlying metal catalysts.…”

“…[53],w ith permission from The RoyalS ocietyofC hemistry. [53] Chem.E ur.J.2019, 25,7779 -7797 www.chemeurj.org As discussed earlier,m etal oxides can act either as co-catalysts or as supports that give rise to beneficial metal-support interactions with their overlying metal catalysts. [55] Typically,m etalsupport interactions are characterized by either partial charge transfer betweent he support itself and the supported metal catalysto rachange in the lattice parameter of the metal catalyst, [56] and these have been previously noted with metal oxide supports such as but not limited to TiO 2 ,C eO 2 ,M oO 2 ,W O 2 , SnO 2 ,a nd RuO 2 .…”

“…Specifically, an earunity occupancy of the e g orbitalo ft hese surface transition-metal ions coupledw ith ah igh degree of covalency with respect to bonding to oxygen can collectively enhancet he intrinsic activity forO ER in alkaline solution. [73] Though RuO 2 is ah ighly effective [53],with permission from The Royal Society of Chemistry. [53] catalystf or OER, Ru is still relatively expensivea sc ompared with other earth-abundant metals.N ot surprisingly,p erovskite oxides, such as but not limited to LaMnO 3 ,S rRuO 3 ,a nd LaCoO 3 ,h ave attracted significant attention and promisea s OER catalysts.…”

“…[73] Though RuO 2 is ah ighly effective [53],with permission from The Royal Society of Chemistry. [53] catalystf or OER, Ru is still relatively expensivea sc ompared with other earth-abundant metals.N ot surprisingly,p erovskite oxides, such as but not limited to LaMnO 3 ,S rRuO 3 ,a nd LaCoO 3 ,h ave attracted significant attention and promisea s OER catalysts. [74] In our group, we prepared as eries of lanthanum nickel oxide (LaNiO 3 )n anorods [1] prepared by using a) as imple and novel template-assisted co-precipitation methodo fl anthanum hydroxide-nickel hydroxide precursors followed by b) am ild annealing of as-prepared lanthanum hydroxide-nickel oxyhydroxide composite nanorods, as shown in Figure 7A-D.…”