Combustion of ethanol (EtOH) at low temperatures has been studied using titania- and silica-supported platinum nanocrystallites with different sizes in a wide range of 1~25 nm, to see if EtOH can be used as a clean, alternative fuel, i.e., one that does not emit sulfur oxides, fine particulates and nitrogen oxides, and if the combustion flue gas can be used for directly heating the interior of greenhouses. The results of H2-N2O titration on the supported Pt catalysts with no calcination indicate a metal dispersion of 0.97±0.1, corresponding to ca. 1.2 nm, while the calcination of 0.65% Pt/SiO2 at 600 and 900℃ gives the respective sizes of 13.7 and 24.6 nm when using X-ray diffraction technique, as expected. A comparison of EtOH combustion using Pt/TiO2 and Pt/SiO2 catalysts with the same metal content, dispersion and nanoparticle size discloses that the former is better at all temperatures up to 200℃, suggesting that some acid sites can play a role for the combustion. There is a noticeable difference in the combustion characteristics of EtOH at 80~200℃ between samples of 0.65% Pt/SiO2 consisting of different metal particle sizes; the catalyst with larger platinum nanoparticles shows higher intrinsic activity. Besides the formation of CO2, low-temperature combustion of EtOH can lead to many other pathways that generate undesired byproducts, such as formaldehyde, acetaldehyde, acetic acid, diethyl ether, and ethylene, depending strongly on the catalyst and reaction conditions. A 0.65% Pt/SiO2 catalyst with a Pt crystallite size of 24.6 nm shows stable performances in EtOH combustion at 120℃ even for 12 h, regardless of the space velocity allowed.

Abstract
 1. 서 론
 2. 재료 및 방법
  2.1. Pt 담지 촉매제조
  2.2. H2-N2O titration에 의한 H2 등온흡착
  2.3. 엑스선회절(X-ray diffraction, XRD) 측정
  2.4. 촉매연소반응
 3. 결과 및 고찰
  3.1. Pt의 입자크기 결정
  3.2. 담지 Pt 촉매상에서 에탄올 연소반응
  3.3. 저온 에탄올 연소반응에 대한 촉매의 안정성
 4. 결 론
 REFERENCES

• 김문현(대구대학교 공과대학 환경공학과) | Moon Hyeon Kim (Department of Environmental Engineering, Daegu University) Corresponding author