Suppression of Carbon Monoxide Poisoning in Proton Exchange Membrane Fuel Cells via Gold Nanoparticle/Titania Ultrathin Film Heterogeneous Catalysts

Abstract

Titania (TiO 2 )-supported gold (Au) nanoparticles (NPs) have long been considered as a promising solution for carbon monoxide (CO) poisoning in proton exchange membrane fuel cells (PEMFCs) as they can efficiently catalyze CO oxidation reaction. Nevertheless, the actual application in functioning PEMFCs has been rarely reported primarily due to the challenges of synthesizing and incorporating the oxidation catalyst in manners compatible with the structure and fabrication of PEMFCs. Here we successfully incorporate the Au NPs/TiO 2 catalyst into PEMFCs and demonstrate an excellent CO elimination function, improving the performance and CO tolerance of PEMFCs; we combine an ultrathin TiO 2 layer (<1 nm) deposited on a Nafion membrane via the low-temperature atomic layer deposition (ALD) and a monolayer of Au NPs assembled on the top of the ultrathin TiO 2 using the Langmuir−Blodgett method. An over 30% enhanced maximum power output is achieved under the presence of a trace amount of CO. Even under highly concentrated CO (0.1%), a less than 10% performance decrease occurs with the incorporation of Au NPs/TiO 2 , in contrast to a nearly 70% performance decrease observed in the control device. The results represent the first experimental implementation of Au NPs/TiO 2 catalysts in PEMFCs and the confirmation of their effectiveness for mitigating the CO poisoning effect.

Subnanometer high-entropy alloy nanowires enable remarkable hydrogen oxidation catalysis

“…20). Considering the resistance to CO poisoning of catalyst is a key factor for hydrogen fuel cell [25][26][27] , the HOR performance of HEA SNWs/C and other references were investigated in the presence of 1000 ppm CO. It is noted that the limiting current density of HEA SNWs/C decreases only by 5.4% at 100 mV vs. RHE, which is smaller than those of HEA NPs/C (6.2%), PtRu/C (21.3%) and Pt/C (22.7%), suggesting the significantly enhanced resistance to CO poisoning of HEA SNWs/C (Supplementary Fig.…”

The Role of Titania Surface Coating by Atomic Layer Deposition in Improving Osteogenic Differentiation and Hard Tissue Formation of Dental Pulp Stem Cells

“…[ 19 ] Titania was deposited onto the PB films using ALD (Cambridge Nanotech Savannah 100), conducted at the Center for Functional Nanomaterials in Brookhaven National Laboratory. We followed the protocol developed from our previous studies, [ 28 ] atomically precise growth of titania thin film was deposited by pursing titanium isopropoxide as precursor and H 2 O as oxidizer for 50 cycles at 80 °C under N 2 gas environment. The titania thickness deposited on Si substrate was measured by ellipsometry, which is linearly dependent to cycle numbers up to 30 cycles, given a 0.068 nm/cycles growth rate, as shown in Figure A.…”

“…We therefore applied atomic layer deposition (ALD) method, which is a well-known process to deposit a homogeneous thin layer of metal oxide onto large-scale surface. [26] Furthermore, ALD process has been developed to conduct at lower temperature, [27,28] which allows deposition onto heat-sensitive materials, such as polymer and organic biomaterials. [29,30] To explore the influence of titania and mechanical properties of the substrate on DPSCs differentiation and biomineralization, we chose to deposit a 3 nm layer of titania onto PB substrates with two different thicknesses, where the influence of mechanical differences has been well studied in our previous works.…”

Combination of 3D Printing and ALD for Dentin Fabrication from Dental Pulp Stem Cell Culture

“…The depositions were performed by exposure to the following steps: (1) titanium (IV) isoporpoxide for 0.5 s, exposed for 6 s, and then purged with nitrogen for 12 s and (2) water vapor for 0.4 s, exposed for 6 s, and then purged with nitrogen for 12 s. These two steps were repeated for 50 cycles. 24 Sample Sterilization. Due to the low glass-transition temperature of around 60 °C of PLA and the hydrolysis degradation property, autoclaving, which reaches temperatures in excess of 120 °C with high humidity, is not an appropriate sterilization technique.…”

“…In addition, the ALD method normally involves high-temperature deposition, but in order to enable coating PLA surfaces, a low-temperature method was developed specifically for coating polymers. 24 When materials are implanted in vivo, ECM proteins are known to adsorb on their surfaces. 25,26 In order to better simulate the actual conditions within the stem cell niche, the scaffolds were also coated with ECM proteins, and the influence of all these materials, separately and in combination, was studied with respect to inducing differentiation and biomineralization of the DPSCs in the absence of chemical inducers.…”