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Three-dimensionally ordered macroporous La 0.6 Sr 0.4 CoO 3 (3DOM LSCO) and its supported gold and manganese oxide ( y Mn 3 O 4 - z Au/3DOM LSCO; y = 0.75–2.50 wt%, z = ca. 2.0 wt%) nanoparticles (NPs) were prepared using the polymethyl methacrylate-templating, polyvinyl alcohol-protected reduction, and physical adsorption methods, respectively. Physicochemical properties of the samples were characterized by means of numerous techniques, and their catalytic activities were evaluated for the oxidation of toluene. It is shown that the 3DOM LSCO in y Mn 3 O 4 - z Au/3DOM LSCO with a surface area of 20–24 m 2 /g displayed a rhombohedral crystal structure, and Mn 3 O 4 (size: 5–12 nm) and Au (size: 3–4 nm) NPs were highly dispersed on the surface of 3DOM LSCO. There were good correlations of adsorbed oxygen species concentration and low-temperature reducibility with catalytic activity of the sample. The 1.67Mn 3 O 4 -2Au/3DOM LSCO sample performed the best, giving the T 50% and T 90% (temperatures required for achieving toluene conversions of 50 and 90%) of 214 and 230 °C at a space velocity of 20,000 mL/(g h), respectively. The introduction of water vapor to the reaction system caused a partial deactivation of the 1.67Mn 3 O 4 -2Au/3DOM LSCO sample, and such a deactivation was reversible. The apparent activation energies (41.7–47.4 kJ/mol) obtained over y Mn 3 O 4 -2Au/3DOM LSCO were lower than those (49.2–56.8 kJ/mol) obtained over 3DOM LSCO, 2Au/3DOM LSCO, and 1.56Mn 3 O 4 -2Au/Bulk LSCO. It is concluded that the large surface area, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between Au or Mn 3 O 4 NPs and 3DOM LSCO were responsible for the good catalytic performance of 1.67Mn 3 O 4 -2Au/3DOM LSCO. [ABSTRACT FROM AUTHOR]

Three-dimensionally ordered macroporous (3DOM) Mn 2 O 3 -supported AuPd y alloy ( x AuPd y /3DOM Mn 2 O 3 ; x = 1.0–3.8 wt%; Pd/Au molar ratio : y = 1.85, 1.92) catalysts were prepared using the polymethyl methacrylate-templating and polyvinyl alcohol-protected reduction methods, respectively. Physicochemical properties of the samples were characterized by means of numerous techniques, and their catalytic activities were evaluated for toluene oxidation. It is found that the AuPd y alloy nanoparticles (NPs) with an particle size of 2–4 nm were uniformly dispersed on the surface of 3DOM Mn 2 O 3 , and the 3.8AuPd 1.92 /3DOM Mn 2 O 3 sample performed the best: the temperature at 90% toluene conversion was 162 °C at 40,000 mL/(g h). Furthermore, the 3.8AuPd 1.92 /3DOM Mn 2 O 3 sample was highly active even after calcination at 700 °C. The introduction of water vapor to the feedstock induced a positive effect on toluene oxidation over 3.8AuPd 1.92 /3DOM Mn 2 O 3 , but a negative effect over 1.9Au/3DOM Mn 2 O 3 or 1.9Pd/3DOM Mn 2 O 3 . The excellent catalytic activity, thermal stability, and water resistance of 3.8AuPd 1.92 /3DOM Mn 2 O 3 were associated with its good activation adsorption of oxygen on AuPd 1.92 NPs and strong interaction between noble metal NPs and 3DOM Mn 2 O 3 . The 3DOM Mn 2 O 3 -supported AuPd y alloy NPs are promising industrial catalysts for efficient removal of volatile organic compounds. [ABSTRACT FROM AUTHOR]

The polymethyl methacrylate-templating and polyvinyl alcohol-protected reduction routes were adopted to prepared three-dimensionally ordered macroporous (3DOM) Co 3 O 4 and its supported gold–palladium alloy ( x AuPd/3DOM Co 3 O 4 , x = 0.50–1.99 wt% and Au/Pd mass ratio = 1:1) nanocatalysts. The 3DOM Co 3 O 4 supported Au–Pd samples performed much better than supported single Au or Pd samples, with the 1.99AuPd/3DOM Co 3 O 4 sample showing the best performance: the T 10% , T 50% , and T 90% (temperatures required for achieving toluene conversions of 10%, 50%, and 90%) were 145, 164, and 168 °C at a space velocity of 40,000 mL/(g h), respectively. The 3DOM Co 3 O 4 supported Au–Pd nanocatalysts also exhibited better catalytic stability and more moisture-tolerant ability than the supported Au or Pd samples for toluene oxidation. The apparent activation energies (33–41 kJ/mol) over x AuPd/3DOM Co 3 O 4 were much lower than those (52–112 kJ/mol) over 3DOM Co 3 O 4 and supported single Au or Pd samples, with the 1.99AuPd/3DOM Co 3 O 4 sample exhibiting the lowest apparent activation energy (33 kJ/mol). It is concluded that better oxygen activation ability and stronger noble metal–3DOM Co 3 O 4 interaction were responsible for the excellent catalytic performance of 1.99AuPd/3DOM Co 3 O 4 . [ABSTRACT FROM AUTHOR]

[Display omitted] • Single atom Pt catalysts are synthesized via the impregnation-pyrolysis method. • 0.5 Pt 1 /Fe 2 O 3 exhibits high photothermal catalytic activity for toluene removal. • The Vis-IR light plays a critical role for toluene complete oxidation. • Possible photothermal catalytic mechanism for toluene oxidation is proposed. • The solar light driven photothermal catalytic purification technique is developed. In this work, Fe 2 O 3 supported single atom Pt (x Pt 1 /Fe 2 O 3 , x = 0.25 and 0.5 wt%) catalysts (SACs) are synthesized via a novel and simple impregnation-pyrolysis method. HAADF-STEM images show that Pt is atomically dispersed on the surface of Fe 2 O 3. All samples exhibit good light-thermal conversion efficiency, which can increase the surface temperature of catalysts to 210 °C. The 0.5 Pt 1 /Fe 2 O 3 exhibits the best photothermal catalytic performance (the toluene conversion and CO 2 yield are 95 % and 87 %, respectively) for toluene oxidation under the irradiation of simulated sunlight with light intensity of 720 mW/cm2, which is attributed to its good light-thermal conversion efficiency and low temperature reducibility. The Vis-IR light plays a critical role in the photothermal catalytic oxidation of toluene in the whole solar spectrum. Furthermore, the possible photothermal catalytic reaction pathway of toluene oxidation is proposed based on the TD-GC/MS and in-situ DRIFTS experiments. [ABSTRACT FROM AUTHOR]

Three-dimensionally ordered mesoporous Cr 2 O 3 ( meso -Cr 2 O 3 ) and its supported Au, Pd, and Au–Pd (0.90 wt% Au/ meso -Cr 2 O 3 , 1.00 wt% Pd/ meso -Cr 2 O 3 , and x Au 1 Pd 2 / meso -Cr 2 O 3 ( x = 0.50–1.95 wt%) catalysts were prepared using the KIT-6-templating and polyvinyl alcohol-protected reduction methods, respectively. Physicochemical properties of the samples were characterized by means of numerous techniques, and their catalytic activities were evaluated for the oxidation of toluene. It is found that the meso -Cr 2 O 3 with a high surface area of 74 m 2 /g was rhombohedral in crystal structure and the noble metal nanoparticles (NPs) with a size of 2.9–3.7 nm were uniformly dispersed on the surface of meso -Cr 2 O 3 . The 1.95Au 1 Pd 2 / meso -Cr 2 O 3 sample performed the best: the T 10% , T 50% , and T 90% (temperatures required for achieving toluene conversions of 10, 50, and 90%) were 87, 145, and 165 °C at a space velocity of 20,000 mL/(g h), respectively, and the apparent activation energy was the lowest (31 kJ/mol) among all of the samples. The effect of moisture on the catalytic activity of the 1.95Au 1 Pd 2 / meso -Cr 2 O 3 sample was also examined. It is concluded that the excellent catalytic performance of 1.95Au 1 Pd 2 / meso -Cr 2 O 3 was associated with its small Au–Pd particle size, high adsorbed oxygen species concentration, good low-temperature reducibility, and strong interaction between Au–Pd NPs and meso -Cr 2 O 3 . [ABSTRACT FROM AUTHOR]

Three-dimensionally ordered macro-/mesoporous silica (3DOM SiO 2 )-supported manganese oxide and gold nanocatalysts ( y Au/ z MnO x /3DOM SiO 2 , y = 0–0.95 wt%; z = 2.7–15.4 wt% (weight percentage of Mn 2 O 3 )) were prepared using the polymethyl methacrylate-templating, incipient wetness impregnation, and polyvinyl alcohol-protected reduction methods, respectively. It is shown that the y Au/ z MnO x /3DOM SiO 2 samples displayed a high-quality 3DOM architecture with macropores (180–200 nm in diameter) and mesopores (4–6 nm in diameter) and a surface area of 220–318 m 2 /g. MnO x nanoparticles (NPs) with a size of 18.7–25.7 nm were dispersed on the surface of 3DOM SiO 2 , and Au NPs with a size of 3.6–3.8 nm were uniformly dispersed on the surface of z MnO x /3DOM SiO 2 . The 0.93Au/11.2MnO x /3DOM SiO 2 sample performed the best (the temperature required for achieving a 90% toluene conversion was 255 °C at space velocity = 20,000 mL/(g h)) for toluene oxidation. It is concluded that the higher oxygen adspecies concentration, better low-temperature reducibility, and stronger interaction between Au and MnO x NPs as well as the unique bimodal porous structure were responsible for the good catalytic performance of 0.93Au/11.2MnO x /3DOM SiO 2 . [ABSTRACT FROM AUTHOR]

Three-dimensionally ordered macro-/mesoporous 26.9 wt% CeO 2 –Al 2 O 3 (denoted as 3DOM 26.9CeO 2 –Al 2 O 3 )-supported noble metal nanocatalysts ( x M/3DOM 26.9CeO 2 –Al 2 O 3 , x = 0.27–0.81 wt%; M = Au, Ag, Pd, and Pt) were prepared using the polymethyl methacrylate-templating and polyvinyl pyrrolidone- or polyvinyl alcohol-protected reduction methods, respectively. It is shown that the x M/3DOM 26.9CeO 2 –Al 2 O 3 samples displayed a high-quality 3DOM architecture with a bimodal pore (macropore size = 180–200 nm and mesopore size = 4–6 nm) structure and a surface area of 102–108 m 2 /g, with the noble metal nanoparticles (3–4 nm in size) being highly dispersed on the 3DOM 26.9CeO 2 –Al 2 O 3 surface. The 0.27Pt/3DOM 26.9CeO 2 –Al 2 O 3 sample performed the best ( T 90% = 198 °C at space velocity = 20,000 mL/(g h)) for toluene oxidation. The addition of moisture to the feedstock induced a positive effect on catalytic activity. The apparent activation energies obtained over the x M/3DOM 26.9CeO 2 –Al 2 O 3 samples were in the range of 46–100 kJ/mol, with the 0.27Pt/3DOM 26.9CeO 2 –Al 2 O 3 sample possessing the lowest apparent activation energy. It is concluded that the good catalytic performance of 0.27Pt/3DOM 26.9CeO 2 –Al 2 O 3 was associated with its higher adsorbed oxygen species concentration, better low-temperature reducibility, and stronger interaction between Pt and 3DOM 26.9CeO 2 –Al 2 O 3 as well as the unique bimodal porous structure. [ABSTRACT FROM AUTHOR]

Highlights: [•] 3DOM La0.6Sr0.4MnO3 (LSMO) is prepared by polymethyl methacrylate-templating method. [•] xAu/LSMO catalysts are prepared by the polyvinyl alcohol-protected reduction method. [•] xAu/LSMO perform excellently in the oxidation of CO and toluene. [•] Activity is governed by Oads content, reducibility, and strong Au–LSMO interaction. [ABSTRACT FROM AUTHOR]

Highlights: [•] 3DOM LaCoO3 is prepared by the polymethyl methacrylate-templating method. [•] xAu/3DOM LaCoO3 are prepared by the polyvinyl alcohol-protected reduction method. [•] xAu/3DOM LaCoO3 show high surface area and Oads concentration and good reducibility. [•] xAu/3DOM LaCoO3 perform excellently in the oxidation of CO and toluene. [•] Activity is governed by Oads content, reducibility, and strong Au–LaCoO3 interaction. [Copyright &y& Elsevier]