申論題 - 阿摩線上測驗

申論題資訊

試卷：110年 - 110 國立中央大學_碩士班招生考試_化學工程與材料工程學系/甲組(一般生):化工熱力學及化學反應工程#105938
科目：研究所、轉學考(插大)◆化工熱力學及化學反應工程
年份：110年
排序：0

題組內容

1. Titanium dioxide is a wide-bandgap seniconductor that is considered as an insulating dielectric in VLSI capacitors and for use in solar applications such as solar cells and photocatalyst. Thin films of TiO₂ can be prepared using chemical vapor deposition from gascous titanium tetra-isopropoxide (TTIP). The overall reaction is

Ti(OC₃H₇)4 → TO₂+4C₃H₆+2H₂O

The reaction mechanism in a CVD is believed to be

TTIP (g) + TTIP (g)

I(g) + P (g)
I(g)+S

I．S

I．S → TiO₂+ P₂(g)

Where I is an active intermediate, S is an active site, Pi is one set of reaction products (e.g. H₂O, C₃H₆) and P₂ is another set. Assuming the homogeneous gas-phase reaction for TTIP is in equilibrium, please answer the following question

申論題內容

(b) (8%) The experimental results show that at 200℃ the reaction is second order at low partial pressure of TTIP and zero order at high partial pressures. While at higher temperature (300 ℃ ) the reaction is second order in TTIP over the entire pressure range. Discuss these results based on the rate law derived above. [Hint: adsorption is exothermic in general]