Catalysis of Methanol‐Air Mixture Using Platinum Nanoparticles for Microscale Combustion

Abstract

High surface area, active catalysts containing dispersed catalytic platinum nanoparticles (d p ∼ 11.6 nm) on a cordierite substrate were fabricated and characterized using TEM, XRD, and SEM. The catalyst activity was evaluated for methanol oxidation. Experimental results were obtained in a miniature-scale continuous flow reactor. Subsequent studies on the effect of catalyst loading and reactor flow parameters are reported. Repeat tests were performed to assess the stability of the catalyst and the extent of deactivation, if any, that occurred due to restructuring and sintering of the particles. SEM characterization studies performed on the postreaction catalysts following repeat tests at reasonably high operating temperatures (∼500• C corresponding to ∼0.3T m for bulk platinum) showed evidence of sintering, yet the associated loss of surface area had minimal effect on the overall catalyst activity, as determined from bulk temperature measurements. The potential application of this work for improving catalytic devices including microscale reactors is also briefly discussed.

A Study of Fuel and Reactor Design for Platinum Nanoparticle Catalyzed Microreactors

“…Material Synthesis. Pt nanoparticles were synthesized using a colloidal synthesis technique delineated by Bonet et al [50] and further specifics detailed elsewhere [48]. The ethylene glycol-based (EG, 99.8% purity, Sigma Aldrich) synthesis incorporated hexachloroplatinic acid precursor (H 2 PtCl 6 , ACS reagent grade, Sigma Aldrich) stabilized by polyvinylpyrrolidone (PVP, MW 29,000, Sigma Aldrich).…”

“…The substrates were coated with cleaned Pt nanoparticles using a draw-coating method and allowed to dry at ambient conditions. Refer to Applegate et al [48] for preparation details. This technique deposited a single coating to the base of each channel (estimated to be 10 mg Pt per deposition).…”

“…Our previous studies involved catalytic combustion and room temperature ignition of methanol-air mixtures [48,49]. These studies demonstrated sustained and repeatable methanol combustion using platinum nanoparticles within cordierite substrates.…”

Catalytic combustion of methane, methanol, and ethanol in microscale combustors with Pt/ZSM-5 packed beds

“…Most reports on micro combustion of methanol and ethanol were focused on the integrated reforming process including a catalytic combustor [17][18][19][20]. The direct combustion of methanol and ethanol in catalytic combustors were less investigated [21][22][23][24][25]. Applegate et al [23] performed methanol combustion in a catalyst reactor with square channels (0.85 mm  0.05 mm).…”

“…The direct combustion of methanol and ethanol in catalytic combustors were less investigated [21][22][23][24][25]. Applegate et al [23] performed methanol combustion in a catalyst reactor with square channels (0.85 mm  0.05 mm). The impact factors on catalyst activity were investigated, but the estimated conversion efficiency was relative low.…”