報告書番号

W98015

タイトル（和文）

触媒燃焼における自己振動現象の基礎的検討

タイトル（英文）

Fundamental Study of self-oscillation phenomena in catalytic combustion

概要 （図表や脚注は「報告書全文」に掲載しております）

超低NOx触媒燃焼器に用いたRh添加触媒とPd/Pt触媒等の熱分析及び燃焼試験を行い、高温場での活性成分の状態を測定した。その結果、各触媒の重量変化曲線は、昇降温でヒステリシスが発生したが、Rhにより触媒の酸化還元特性が変化し、ヒステリシスは小さくなった。触媒の酸化還元特性へのRh担持量の影響について検討した結果、重量減少率の差はほとんどなかった。熱分析と同じ昇降温条件でのメタン燃焼試験においても、触媒活性にヒステリシスが生じたが、Rhによって昇降温での活性の差が少なくヒステリシスは小さくなった。これらの結果から、Rhによって酸素解離が抑制され、より高温域まで高活性なPdOを保持することにより、自己振動が抑制されると考えられる。また、触媒活性と熱重量変化のヒステリシスに相関があり、触媒の自己振動性及び触媒活性を簡易的に評価できる見通しを得た。

概要 （英文）

Thermal analysis and combustion test of Pd/Pt/Rh catalyst and Pd/Pt catalyst were performed, and the state of the activity ingredient in the high temperature was measured. As a result, oxygen dissociation from each of catalysts was confirmed at over 600℃ of heating process. TG curves of each of catalysts generated hysteresis in heating and cooling process, but it was clear that the oxidation-reduction characteristic of the catalyst was changed and hysteresis become small by adding Rh. The influence of Rh content to the oxidization reduction characteristic of a catalyst was examined. Consequently, ratio of weight was no difference.The activity of methane combustion was compared to Pd/Pt catalyst and Pd/Pt/Rh catalyst in the same thermal analysis condition. As a result, methane conversion generated a hysteresis in heating and cooling. By adding Rh, it was small that activity drops at the high-temperature region and the difference in activity at the heating and cooling process and it was clear that the PdO of high activity is maintained. From variation of hysteresis, self-oscillation suppression assumed that by adding Rh that suppress oxygen dissociation and hold PdO of high activity up to high temperature region.From hysteresis of catalytic activity and weight changes the relevance was found out. It obtained the prospect that self-oscillation could easily be evaluated from weight change hysteresis and combustion test.

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