Abstract
PtSn/θ-Al2O3 catalysts with different amounts of K (0.14, 0.22, 0.49, 0.72, and 0.96 wt%) are prepared to investigate the K effects on the PtSn catalyst in propane dehydrogenation (PDH). KPtSn catalyst with 0.xx wt% K, 0.5 wt% Pt and 0.75 wt% Sn is designated as xx-KPtSn. PDH was performed at 873 K and a gas hourly space velocity (GHSV) of 53,000 mL/gcat h. The temperature-programmed desorption (NH3-TPD), temperature-programmed reduction (TPR) and CO chemisorption of the KPtSn catalysts with K added revealed the potassium addition blocked the acid sites, promoted the reduction of Sn oxide and decreased the Pt dispersion. The formations of cracking products and higher hydrocarbons on acid sites were suppressed by the K effect of blocking the acid sites. In contrast, K addition at more than 0.72 wt% rather increased cracking products and the amount of coke, resulting in the severe deactivation of catalysts. The high cracking products on the KPtSn catalysts with the high amount of K should not be related to the acid sites, because the acid sites were monotonously decreased with an increase in the amount of K. Instead, the potassium affected the characteristics of PtSn. The interaction between Pt and Sn could be weakened by enriching the reduced Sn, because the K component promoted the reduction of Sn oxide in the TPR experiments. Therefore, the 14-KPtSn catalyst with the low amount of K exhibits the highest stability and selectivity among the prepared KPtSn catalysts due to the compromise of the advantageous (blocking the acid sites) and bad (weakening the interaction between Pt and Sn) effects of the K addition in PDH.
| Original language | English |
|---|---|
| Pages (from-to) | 123-140 |
| Number of pages | 18 |
| Journal | Research on Chemical Intermediates |
| Volume | 42 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2016 Jan 1 |
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Keywords
- K(PtSn)/θ-AlO catalyst
- Propane dehydrogenation
- Propylene
- PtSn alloy formation
ASJC Scopus subject areas
- Chemistry(all)
Cite this
Effect of potassium addition on bimetallic PtSn/θ-Al2O3 catalyst for dehydrogenation of propane to propylene. / Lee, Mi Hyun; Nagaraja, Bhari Mallanna; Natarajan, Prakash; Truong, Ngoc Thanh; Lee, Kwan Young; Yoon, Sungho; Jung, Kwang Deog.
In: Research on Chemical Intermediates, Vol. 42, No. 1, 01.01.2016, p. 123-140.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effect of potassium addition on bimetallic PtSn/θ-Al2O3 catalyst for dehydrogenation of propane to propylene
AU - Lee, Mi Hyun
AU - Nagaraja, Bhari Mallanna
AU - Natarajan, Prakash
AU - Truong, Ngoc Thanh
AU - Lee, Kwan Young
AU - Yoon, Sungho
AU - Jung, Kwang Deog
PY - 2016/1/1
Y1 - 2016/1/1
N2 - PtSn/θ-Al2O3 catalysts with different amounts of K (0.14, 0.22, 0.49, 0.72, and 0.96 wt%) are prepared to investigate the K effects on the PtSn catalyst in propane dehydrogenation (PDH). KPtSn catalyst with 0.xx wt% K, 0.5 wt% Pt and 0.75 wt% Sn is designated as xx-KPtSn. PDH was performed at 873 K and a gas hourly space velocity (GHSV) of 53,000 mL/gcat h. The temperature-programmed desorption (NH3-TPD), temperature-programmed reduction (TPR) and CO chemisorption of the KPtSn catalysts with K added revealed the potassium addition blocked the acid sites, promoted the reduction of Sn oxide and decreased the Pt dispersion. The formations of cracking products and higher hydrocarbons on acid sites were suppressed by the K effect of blocking the acid sites. In contrast, K addition at more than 0.72 wt% rather increased cracking products and the amount of coke, resulting in the severe deactivation of catalysts. The high cracking products on the KPtSn catalysts with the high amount of K should not be related to the acid sites, because the acid sites were monotonously decreased with an increase in the amount of K. Instead, the potassium affected the characteristics of PtSn. The interaction between Pt and Sn could be weakened by enriching the reduced Sn, because the K component promoted the reduction of Sn oxide in the TPR experiments. Therefore, the 14-KPtSn catalyst with the low amount of K exhibits the highest stability and selectivity among the prepared KPtSn catalysts due to the compromise of the advantageous (blocking the acid sites) and bad (weakening the interaction between Pt and Sn) effects of the K addition in PDH.
AB - PtSn/θ-Al2O3 catalysts with different amounts of K (0.14, 0.22, 0.49, 0.72, and 0.96 wt%) are prepared to investigate the K effects on the PtSn catalyst in propane dehydrogenation (PDH). KPtSn catalyst with 0.xx wt% K, 0.5 wt% Pt and 0.75 wt% Sn is designated as xx-KPtSn. PDH was performed at 873 K and a gas hourly space velocity (GHSV) of 53,000 mL/gcat h. The temperature-programmed desorption (NH3-TPD), temperature-programmed reduction (TPR) and CO chemisorption of the KPtSn catalysts with K added revealed the potassium addition blocked the acid sites, promoted the reduction of Sn oxide and decreased the Pt dispersion. The formations of cracking products and higher hydrocarbons on acid sites were suppressed by the K effect of blocking the acid sites. In contrast, K addition at more than 0.72 wt% rather increased cracking products and the amount of coke, resulting in the severe deactivation of catalysts. The high cracking products on the KPtSn catalysts with the high amount of K should not be related to the acid sites, because the acid sites were monotonously decreased with an increase in the amount of K. Instead, the potassium affected the characteristics of PtSn. The interaction between Pt and Sn could be weakened by enriching the reduced Sn, because the K component promoted the reduction of Sn oxide in the TPR experiments. Therefore, the 14-KPtSn catalyst with the low amount of K exhibits the highest stability and selectivity among the prepared KPtSn catalysts due to the compromise of the advantageous (blocking the acid sites) and bad (weakening the interaction between Pt and Sn) effects of the K addition in PDH.
KW - K(PtSn)/θ-AlO catalyst
KW - Propane dehydrogenation
KW - Propylene
KW - PtSn alloy formation
UR - http://www.scopus.com/inward/record.url?scp=84958115897&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84958115897&partnerID=8YFLogxK
U2 - 10.1007/s11164-015-2370-1
DO - 10.1007/s11164-015-2370-1
M3 - Article
VL - 42
SP - 123
EP - 140
JO - Research on Chemical Intermediates
JF - Research on Chemical Intermediates
SN - 0922-6168
IS - 1
ER -