Facile Synthesis of Pt_xNi_y Catalyst Supported on Carbon for Low Temperature H₂–SCR

Abstract

PtNi alloy nanoparticles supported on carbon (XC-72) are synthesized via a one-pot synthetic approach. This synthesized bimetallic composite offers several advantages, such as reduction of precious Pt along with an increase in activity due to the modified electronic structure. The prepared PtNi/C catalysts were employed as catalysts for NO removal both in a fixed-bed reactor and in a newly designed gas diffusion reactor. The performances of all prepared PtNi/C catalysts were higher than Pt/C at the same conditions and maintained a stable NO removal at a wide temperature window (100–300 °C), especially for Pt65Ni35 (more than 95% from 120 to 300 °C). This is attractive for low temperature SCR technology. According to XPS analysis, the surface layer phase was comprised of Pt contents with Ni being localized beneath the successive layers until Ni content increased to 67% mole ratio. The surface presence of Ni significantly affects the Pt electronic structure and raises the mass specific activity of Pt. Meanwhile, PtNi/C catalysts were introduced in a new gas diffusion reactor to remove NO under quantitatively less catalysts (30 mg), high NO concentration (1000 ppm), and at a high flow rate (resulting in a very short residence time of 0.09 s) condition. NO removal reaches almost 100% below 95 °C for all the PtNi catalysts and among all Pt65Ni35 exhibited the best performance. In addition, the influence of SO2 on the performance of Pt65Ni35 was also investigated, and the catalysts exposed a good antipoisonous property. The excellent performance of PtNi catalysts and a gas diffusion reactor are strongly recommended for their utilization as highly active and economical technology for NO removal.

FeSTi Superacid Catalyst for NH3-SCR with Superior Resistance to Metal Poisons in Flue Gas

“…Nitrogen oxides (NO x ) are linked to serious environmental problems such as photochemical smog and acid rain, 1,2 and selective catalytic reduction with NH 3 (NH 3 -SCR) is the most efficient method for NO x abatement. 3,4 Although commercial V 2 O 5 −WO 3 (MoO 3 )/TiO 2 catalysts are widely used in the NH 3 -SCR system at present, this material has several disadvantages, including toxicity concerns (due to the incorporation of V), poor resistance to alkali, alkaline-earth, and heavy metals, and a narrow operating temperature window.…”

“…Nitrogen oxides (NO x ) are linked to serious environmental problems such as photochemical smog and acid rain, , and selective catalytic reduction with NH 3 (NH 3 -SCR) is the most efficient method for NO x abatement. , Although commercial V 2 O 5 –WO 3 (MoO 3 )/TiO 2 catalysts are widely used in the NH 3 -SCR system at present, this material has several disadvantages, including toxicity concerns (due to the incorporation of V), poor resistance to alkali, alkaline-earth, and heavy metals, and a narrow operating temperature window. − In a coal-fueled power plant, the NH 3 -SCR unit will normally be located prior to the precipitator to ensure an appropriate temperature and to avoid the deposition of NH 4 HSO 4 . Consequently, the catalyst is exposed to fly ash and various poisoning compounds in the flue gas. , For this reason, the catalytic material must be highly tolerant of such poisoning species.…”

Engineering the Metal–Support Interaction on Pt/TiO2 Catalyst to Boost the H2-SCR of NOx

“…21 In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiment was performed on an FTIR spectrometer (Thermo Scientific Nicolet iS50) using a Harrick DRIFT cell with a gas flow rate of 100 mL/min. 17 The background was first collected in flowing He and automatically subtracted from the sample spectrum. All spectra were obtained by averaging 64 scans.…”

“…H 2 -SCR catalysts are mainly focused on supported Pt − and Pd-based catalysts, − and Pt catalysts are more active in NO x removal. For diesel passenger cars and high-efficiency gas boilers, the exhaust temperature is typically below 200 °C. , To reduce the cost, developing Pt catalysts with less Pt loading is desirable.…”

Investigation of the hydrothermal aging of an Mn-based mullite SmMn2O5 catalyst of NO oxidation

“…NO x is a highly damaging pollutant, and leads to respiratory stimulation, photochemical smog, acid rain, and harm to crops. [1][2][3] Ammonia selective catalytic reduction (NH 3 -SCR) (2NH 3 + NO + NO 2 / 2N 2 + 3H 2 O) is considered to be effective at removing NO x . To achieve a high SCR efficiency, an NO-to-NO 2 molar ratio of 1 : 1 is required.…”