Decomposition of methanol on partially alumina-encapsulated Pt nanoclusters supported on thin film Al2O3/NiAl(100)

Composition-Tuned Pt-Skinned PtNi Bimetallic Clusters as Highly Efficient Methanol Dehydrogenation Catalysts

“…The 50% reduction in the pure Pt clusters activity in the subsequent cycles may be assigned to the lower accessibility of the reaction sites on the cluster surface. 7 The variation of the D2 desorption temperature versus the BC composition ( Figure 3-d) shows a minimum at Pt0.7Ni0.3. D2 desorbs in the 250-300 K range indicating that Ni alloyed Pt clusters are always catalytically active below room temperature.…”

“…1,2 Although platinum is widely used as (electro)catalyst in the dehydrogenation of methanol (CH3OH), 3,4 its performance is limited by its modest stability and selectivity. [5][6][7] The three main drawbacks of platinum-based anode catalysts are their high cost as methanol bonds breaking requires large amounts of catalyst, 8 their low selectivity to generate hydrogen as end product, and their low stability in presence of carbon monoxide, a by-product of methanol dissociation (i.e. the CO poisoning effect).…”

“…9,10 These crucial challenges require remediation in order to design future high performance fuel cell catalysts, for which fundamental understanding of the reaction kinetics at the atomic and molecular level are required. For this purpose, the reaction kinetics of model catalyst systems such as single Pt atoms, 11 Pt single crystals, [12][13][14] oxide-supported Pt thin films, 15 and Pt nanoparticles, 6,7 have been investigated intensively.…”

Promoted activity of annealed Rh nanoclusters on thin films of Al2O3/NiAl(100) in the dehydrogenation of Methanol-d4

“…Preceding works showed that annealing can alter the morphology, size and structures of oxide-supported nanoclusters; [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] annealing can also induce mass transport and thus encapsulation and oxidation of oxide-supported nanoclusters. 23,[30][31][32][33][34][35][36][37][38] On the other hand, the thermal stability of catalysts, reected in the annealing-induced variation of structures and reactivity, is a major concern for qualied catalysts. [14][15][16][17][18] The objective of the present work was to study the effect of annealing on the reactivity of oxide-supported rhodium (Rh) clusters in the decomposition of methanol.…”

Investigation of Thermal Stability and Reactivity of Rh Nanoclusters on an Ultrathin Alumina Film

“…As the reactivity of catalysts is largely associated with their structures [1][2][3][4][5] and as catalyzed reactions could proceed at elevated temperature, a knowledge of thermal stability of such structures and how they evolve with elevated temperature becomes desirable. Preceding work showed that elevated temperature can alter the morphologies, sizes and structures of oxide-supported metal nanoclusters, typical catalysts [1][2][3][4][5][6][7][8][9][10][11][12][13][14]; it can also induce mass transport and thus encapsulation and oxidation of the oxide-supported nanoclusters [1][2][3][4][5]11,[15][16][17][18][19][20]. The objective of the present work is to study the effect of elevated temperature on the structure and morphology of oxide-supported rhodium (Rh) clusters and examine the effect with catalyzed decomposition of methanol (methanol-d 4 ), which is the principal reaction applied in direct methanol fuel cells (DMFC) [21][22][23][24][25] and also serving as a source of hydrogen.…”