Catalytic Platinum Nanoparticles Decorated with Subnanometer Molybdenum Clusters for Biomass Processing

Abstract

The development of improved technologies for biomass processing into transportation fuels and industrial chemicals is hindered due to al ack of efficient catalysts for selectiveo xygen removal.H ere we report that platinum nanoparticles decorated with subnanometer molybdenum clusters can efficiently catalyzeh ydrodeoxygenation of acetica cid, which serves as am odel biomass compound. In contrast with monometallic Mo catalysts that are inactive and monometallic Pt catalysts that have low activities and selectivities, bimetallic Pt-Mo catalysts exhibit synergistic effects with high activities and selectivities. The maximum activity occurs at aP tt oM om olar ratio of three. Although Mo atoms themselvesa re catalytically inactive, they serve as preferentialb inding anchors for oxygen atoms while ac atalytic transformation proceeds on neighboring surfaceP ta toms. Beyond biomass processing, Pt-Mo nanoparticles are promisingc atalysts for aw ide variety of reactionst hat requireatransformation of molecules with an oxygen atom and, more broadly, in other fieldso fs cience and technology that require tuning of surface-oxygen interactions.Promising new technologiesf or biomassc onversion into fuels and chemical feedstocks rely on production of bio-oils, which need to be upgraded to removeo xygen-containing hydrocarbons (oxygenates) andw ater. [1] In contrast with fossil fuels that are usually contaminatedw ith sulfur and nitrogen-containing compounds but are free of oxygenates,a ll biomass contains oxygen. Removalo fo xygenates is required because ah igh oxygen concentration makes bio-oils acidic and corrosive, unstable during storage, and less energetically valuable per unit weightt han petroleum-derived hydrocarbons. Althoughe fficient pyrolysis and liquefaction processes have been recently developed for the production of bio-oils,o xygen removal from these bio-oils remains challenging. Current technologies for removingo xygen in the presence of hydrogen (hydrodeoxygenation) rely mostly on traditionalp etroleum refining catalysts, which are not optimizedf or biomass processing and, as a result, suffer from insufficienta ctivity, selectivitya nd stability. More efficientu pgrading technologiesa re, therefore, needed for the developmento fs ustainable energy and chemical resources. [1b, d-f] Among major oxygenate types in bio-oils, carboxylic acids are some of the most challenging because their hydrodeoxygenationr ates are usuallya no rder of magnitudel ower. [2] Therefore, acetic acid, the simplest carboxylic acid, is often used as am odel compound in the development of new hydrodeoxygenation processes. [2a,c, 3] Furthermore, acetic acid itself is as ignificant component of bio-oils with ac oncentration from typically5 -8 wt % [1d, 4] to as high as 32 wt %, depending on the type of the initial biomass. [5] In the development of improved catalysts, multiple metals, supports and reaction conditions were evaluated for acetic acid hydrodeoxygenation. For example, in additiont ot raditionals ulfidedN ia nd Mo-based ca...

Propane Dehydrogenation to Propylene and Propylene Adsorption on Ni and Ni‐Sn Catalysts

“…Similarly constructed periodic surfaces with similar computational settings were previously used successfully for studying adsorption and reactions on Ni [13] and other metal surfaces. [14][15][16][17][18][19][20][21][22][23] Adsorption energies were calculated at 0 K without zero-point energy corrections using as a reference the sum of energies for the corresponding clean surface and an isolated propylene molecule calculated separately. Adsorption energies are reported as positive numbers, À ΔE ads .…”

“…The remaining two bottom layers were constrained at the bulk Ni positions, accounting for the bulk structure. Similarly constructed periodic surfaces with similar computational settings were previously used successfully for studying adsorption and reactions on Ni [13] and other metal surfaces [14–23] …”

Atomic, Molecular and Hybrid Oxygen Structures on Silver

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Acetic Acid Adsorption and Reactions on Ni(110)

“…For these reactions, it is important to determine adsorption modes and surface reactivity of light hydrocarbons, such as acetic acid. Specifically for hydrodeoxygenation technologies for converting biomass into transportation fuels and chemical feedstocks, acetic acid is an actual component of bio-oils and, therefore, it is widely used as a model compound representing carboxylic acids and other oxygen-containing hydrocarbons. − In addition, acetic acid is used as a model compound in the development of improved catalysts for steam reforming of biomass-derived chemicals into synthesis gas for the Fischer–Tropsch process and for the hydrogen production for fuel cells and other applications. , In selective oxidation, the reverse of hydrodeoxygenation, it is desirable to develop efficient catalysts for a single-step process for the production of acetic acid from ethane, ethylene or ethanol. , …”