NO2 감지용 SnO2 후막소자의 제작 및 특성

손종락,한종수 ( Jong Rack Sohn,Jong Soo Han ) 한국공업화학회 1997 공업화학 Vol.8 No.2

NO₂기체의 감지를 위한 sensor의 원료물질로 SnO₂를 사용하였으며 SnCl₄ 용액을 암모니아수로 침전시킨 후 공기중에 하소하여 SnO₂를 제조하였다. SnO₂의 특성을 XRD 및 IR로 연구하였으며 스크린-프린팅법으로 SnO₂후막소자를 제작하였다. 하소온도가 높을수록 SnO₂의 입자의 크기는 결정의 성장으로 증가하였다. 1000℃에서 하소된 SnO₂분말을 가지고 만든 소자를 700℃에서 열처리하여 제작된 SnO₂ 소자는 동작온도 250℃에서 NO₂기체에 대한 우수한 감지특성과 선택성을 나타내었다. SnO₂ as raw material of sensor for NO₂ detection was prepared by precipitating SnCl₄ solution with aqueous ammonia followed by calcining in air. The characterization of SnO₂ was carried out using FT-IR and XRD, and SnO₂ thick film sensor was fabricated by screen-printing method. The paticle size of SnO₂ calcined at higher temperature increased due to the growth of crystalline. SnO₂ sensor fabricated by using SnO₂ sample calcined at 1000℃ followed by heat treatment at 700℃ exhibited excellent sensing characteristics and selectivity for NO₂ gas at the operating temperature of 250℃.

베릴리아 - 실리카 촉매의 특성과 산촉매성질

손종락,박은희,장향자,김해원 ( Jong Rack Sohn,Eun Hee Park,Hyang Ja Jang,Hae Won Kim ) 한국공업화학회 1996 공업화학 Vol.7 No.2

일련의 BeO-SiO₂ 촉매를 염화베릴리움과 sodium silicate 혼합 용액을 공침전법으로 제조하였다. SiO₂에 BeO를 첨가하면 표면적, 산의 양, 산세기, 산촉매활성이 증가하여 BeO 함량이 20㏖%일 때 최대를 나타내었다. X-선 회절로 조사한 결과 400∼500℃에서 소성된 촉매는 무정형으로 존재하였으며 Bro¨nsted 산점과 Lewis 산점 모두를 가지고 있었다. Cumene의 dealkylation 반응에 대한 촉매활성은 촉매의 산의 양과 밀접한 관계를 가졌다. A series of BeO-SiO₂ catalysts were prepared by coprecipitation from the mixed solution of berylium chloride and sodium silicate. The addition of BeO to SiO₂ caused the increase of acidity, acid strength, specific surface area, and acid catalytic activity, giving a maximum at 20 ㏖% of BeO. On the basis of x-ray diffraction pattern, the catalysts calcined at 400∼500℃ were found to be amorphous, having both Bro¨nsted and Lewis acid sites. Catalytic activities for cumene dealkylation were closely correlated with the acidity of catalysts.

The Isosteric Heats of Adsorption of Amines on Paraffin and Polyethyleneglycol

손종락,김종택,Sohn Jong Rack,Kim, Jong Taik Korean Chemical Society 1972 대한화학회지 Vol.16 No.4

Isostric heats of adsorption of amines on paraffin and polyethyleneglycol were measured by gas chromatography. Value with polyethyleneglycol were significantly higher than those with paraffin due to the N-H...O bonding. The contribution of C-H...O bonding to the isosoteric heats of adsorption was negligible. The additional heats of adsorption observed as the sample size increased also increased as the number of amino hydrogen atoms decreased. This tendency was more significant with polyethyleneglycol indicating that strong directing force of amino hydrogen of primary and secondary amines to the surface hinder lateral attractive interaction which could be favored with free orientation.

에틸렌 이량화를 위한 새로운 NiO - ZrO2 / WO3 촉매의 제조와 특성

손종락,신동철,박만영 ( Jong Rack Sohn,Dong Cheol Shin,Man Young Park ) 한국공업화학회 1996 공업화학 Vol.7 No.5

에틸렌 이량화반응을 위한 일련의 NiO-ZrO₂/WO₃촉매를 염화니켈-옥시염화 질코니움 수용액을 공침시키고 ammonium metatungstate용액으로 함침시킨 다음 공기 중에서 소성하여 제조하였다. X-선 회절과 DSC로부터 얻은 결과를 근거로 하면 ZrO₂에 NiO 및 WO₃를 첨가하면ZrO₂와 첨가된 산화물과의 상호작용으로 ZrO₂의 무정형에서 tetragonal phase로의 상전이 온도가 더 높은 온도로 이동되었다. WO₃가 첨가되지 않은 NiO-ZrO₂는 에틸렌 이량화반응에 전혀 촉매 활성을 나타내지 아니 하였으나 WO₃가 첨가된 NiO-ZrO₂/WO₃촉매는 실온에서도 높은 활성을 나타내었다. 이와 같은 NiO-ZrO₂/WO₃의 높은 촉매활성은 WO₃의 유도효과에 의한 산세기의 증가와 밀접한 관련이 있었다. A series of catalysts, NiO-ZrO₂/WO₃ for ethylene dimerization were prepared by coprecipitation from a solution of nickel chloride - zirconium oxychloride mixture followed by dry impregnation with an aqueous solution of ammonium metatungstate and calcination in air. On the basis of the results obtained from x-ray diffraction and DSC, the addition of NiO and WO₃to ZrO₂ shifted the transition of ZrO₂from amorphous to a tetragonal phase toward higher temperatures due to the interaction between Ni0(or W0₃) and ZrO₂. NiO-ZrO₂without W0₃was inactive for the ethylene dimerization, but NiO-ZrO₂/WO₃ was found to be very active even at room temperature. The high catalytic activity of NiO-ZrO₂/WO₃ was closely correlated with the increase of acid strength by the inductive effect of WO₃.

Superacidic Property of $ZrO_2$ Modified with Sulfur Compounds

손종락,김해원,김종택,Jong Rack Sohn,Hae Won Kim,Jong Taik Kim Korean Chemical Society 1987 대한화학회지 Vol.31 No.4

$ZrO_2$의 표면을 $H_2SO_4$로 처리하거나 $SO_2,\;H_2S,\;CS_2$로 처리한 후 산화시킴으로 개질하였다. 처리된 황화합물의 산화종과 산화상태를 적외선분광법과 X-선광전자분광법으로 조사하였다. 처리된 황화합물을 산화시킨 후에는 사용된 황화합물의 종류에는 관계없이 개질된 $ZrO_2$는 모두 강한 산성질을 나타내었다. 개질된 $ZrO_2$가 초강산의 성질을 나타내는 것은 가장 높은 산화상태의 황($SO_4{^{2-}}$)에 기인하였다. $ZrO_2$was modified by treating with $H_2SO_4$ and by treating witb $SO_2,\;H_2S,\;and\;CS_2$ followed by oxidation. The oxidized species and oxidation state of sulfur compounds were investigated by infrared and X-ray photoelectron spectroscopies. The generation of strong acidity of modified $ZrO_2$ was independent of the sulfur source after oxidation. The sulfur ($SO_4{^{2-}}$) in the highest oxidation state was responsible for the superacidic property of the modified $ZrO_2$.

CH3CN 감지용 SnO2 후막소자의 특성과 IR 연구

손종락,박효덕,이덕동 ( Jong Rack Sohn,Hyo Deck Park,Duk Dong Lee ) 한국공업화학회 1997 한국공업화학회 연구논문 초록집 Vol.1997 No.0

NO₂ 감지용 SnO₂ 후막소자의 제작 및 특성

손종락,한종수,Sohn, Jong Rack,Han, Jong Soo 한국공업화학회 1997 공업화학 Vol.8 No.2

$NO_2$기체의 감지를 위한 sensor의 원료물질로 $SnO_2$를 사용하였으며 $SnCl_4$ 용액을 암모니아수로 침전시킨 후 공기중에 하소하여 $SnO_2$를 제조하였다. $SnO_2$의 특성을 XRD 및 IR로 연구하였으며 스크린-프린팅법으로 $SnO_2$후막소자를 제작하였다. 하소온도가 높을수록 $SnO_2$의 입자의 크기는 결정의 성장으로 증가하였다. $1000^{\circ}C$에서 하소된 $SnO_2$분말을 가지고 만든 소자를 $700^{\circ}C$에서 열처리하여 제작된 $SnO_2$소자는 동작온도 $250^{\circ}C$에서 $NO_2$기체에 대한 우수한 감지특성과 선택성을 나타내었다. $SnO_2$ as raw material of sensor for $NO_2$ detection was prepared by precipitating $SnCl_4$ solution with aqueous ammonia followed by calcining in air. The characterization of $SnO_2$ was carried out using FT-IR and XRD, and $SnO_2$ thick film sensor was fabricated by screen-printing method. The particle size of $SnO_2$ calcined at higher temperature increased due to the growth of crystalline. $SnO_2$ sensor fabricated by using $SnO_2$ sample calcined at $1000^{\circ}C$ followed by heat treatment at $700^{\circ}C$ exhibited excellent sensing characteristics and selectivity for $NO_2$ gas at the operating temperature of $250^{\circ}C$.

TiO2 - SiO2 및 H2SO4 으로 개질된 TiO2 - SiO2 의 촉매특성과 산 성질

손종락,장향자 ( Jong Rack Sohn,Hyang Ja Jang ) 한국공업화학회 1990 공업화학 Vol.1 No.1

일련의 TiO₂- SiO₂촉매를 TiCl₄와 NaSiO₃혼합용액을 공침전시켜 제조하였으며 이중 일부의 촉매는 1N H_2SO_4로 처리하여 촉매표면을 개질하였다. 개질된 촉매의 촉매활성은 개질 안된 촉매보다 높은 촉매활성을 나타내었으며 cumene dealkylation 반응에서 보다 2 - propanol dehydration 반응에서 더욱 효과가 크게 나타났다. 개질 안된 촉매의 상기 두 반응에 대한 촉매활성은 산의 양과 관계가 있었다. TiO₂- SiO₂촉매는 비교적 많은 양의 약한 산자리와 작은 양의 강한 산자리를 가졌기 때문에 cumene dealkylation 반응에서 보다 2 - propanol dehydration 반응에 더 높은 촉매활성을 나타내었다. 촉매활성에 미치는 H_2SO_4의 개질효과는 TiO₂함량에 비례하였으며 92 - TiO₂- SiO₂/SO_4^2가 2 - propanol dealkylation 반응에 가장 큰 촉매활성의 증가를 나타내었다. A series of TiO₂- SiO₂catalysts were prepared by coprecipitation from the mixed solution of titanium tetrachloride and sodium silicate. Some of the samples were treated with 1N H_2SO_4 and used as modified catalysts. The catalytic activities of modified catalysts were higher than those of unmodified catalysts, and the effect of modification on the catalytic activity was higher for 2 - propanol dehydration than for cumene dealkylation. The catalytic activity of unmodified catalysts was correlated with their acid amount for the above two reactions. As TiO₂- SiO₂catalysts had relatively large amount of weak acid sites and small amount of strong acid sites, the catalytic activity for 2 - propanol dehydration was higher than that for cumene dealkylation. The effect of modification on catalytic activity increased with increasing TiO₂ content of the catalysts. Actually, 92 - TiO₂- SiO₂/SO_4^2 had the highest increment in catalytic activity and 10 - TiO₂- SiO₂/SO_4^2 had the lowest increment for the 2 - propanol dehydration.

Cation Exchanged Silicate Catalyst for Ethylene Polymerization

손종락,박현배,Jong Rack Sohn,Hyen Bae Park Korean Chemical Society 1982 대한화학회지 Vol.26 No.5

Montmorillonite가 주성분인 산성백토로부터 여러 양이온을 교환시켜 촉매를 제조하여 ethylene의 중합활성에 대하여 연구하였다. $Ni^{2+}$-Mont촉매상에서는 ethylene이 선택적으로 n-butene으로 이량화 되었으며, 그 활성은 150$^{\circ}$C 의 진공온도에서 최고로 나타났다. 그리고 촉매활성의 변화는 촉매의 산도와 밀접한 관계가 있었다. $Ni^{2+}$-Mont 촉매는 ethylene의 중합에 높은 활성을 나타내었으며, 그 활성은 450$^{\circ}C$의 진공온도에서 최고로 나타났다. 그리고 $Cr^{3+}$-Mont의 활성점은 $Cr^{3+}$이온으로 생각되었다. Several cation exchanged-layer silicate catalysts were prepared from acid clay mainly consisted of montmorillonite, and their catalytic activities for the ethylene polymerization were studied at room temperature. It was found that over$Ni^{2+}$ -Mont, dimerization of ethylene to n-butene proceeded selectively.$Ni^{2+}$ -Mont was activated by evacuation at elevated temperature, giving a maximum temperature, 150$^{\circ}$C . The variations in catalytic activities were closely correlated to the acidity of the catalysts.$Cr^{3+}$ -Mont exhibited a high activity for the polymerization, showing, a maximum at the evacuation temperature of 450$^{\circ}C$. The active site in $Cr^{3+}$-Mont was considered to be $Cr^{3+}$ ion.

산화크롬 - 질코니아 촉매의 산화 - 환원거동

손종락,류삼곤 ( Jong Rack Sohn,Sam Gon Ryu ) 한국공업화학회 1992 공업화학 Vol.3 No.4

분말의 Zr(OH)_4를 (NH_4)2_CrO_4수용액에 함침시킨 후 공기중에 소성하여 질코니아에 담지된 산화크롬 촉매를 제조하였다. 제조된 CrO_x/ZrO_2 촉매상에 cumene을 반응시켜 산화-환원 거동을 연구한 결과 크롬의 산화상태가 +6인 chromate형태로 질코니아 표면에 존재할 때는 강한 산점이 생성되어 cumene의 탈알킬화 반응에 촉매활성을 나타내었다. 그러나 많은 양의 Cr^(6+)종은 반응중에 탈수소로 생성된 H_2에 의하여 환원되어 Cr^(3+)종으로 변화되었으며 Cr^(3+)종은 cumene을 탈수소화시켜 α-methyl styrene을 생성하는 반응에 활성점으로 작용하였다. 환원된 Cr^(3+)종은 0_2로 처리하면 다시 Cr^(6+)종으로 되고 따라서 산화된 촉매는 cumene의 탈알킬화 반응에 활성을 나타내었다. Chromium oxide/zirconia catalysts were prepared by dry impregnation of Zr(OH)_4 powder with aqueous solution of (NH_4)_2CrO_4 followed by calcining in air. The redox behavior of prepared catalysts were investigated by reacting cumene as test material over catalysts. As a result it was found that Cr^(6+) species(as chromate) on the surface of catalyst was responsible for the formation of strong acid site and the catalytic activity for the dealkylation of cumene. However, much of the Cr^(6+) species was reduced to Cr^(3+) species by H_2 formed during the catalytic reaction of cumene and the reduced Cr^(3+) species was an active site for dehydrogenation of cumene to form α-methyl styrene. The reduced Cr^(3+) species was also reoxidized to a Cr^(6+) species after treatment with O_2 and consequently the reoxidized catalyst exhibited catalytic activity for the dealkylation reaction of cumene.