A liquid-phase exfoliation of few-layer graphene in tea is considered as one of the alternative approaches for the preparation of environment-friendly graphene. However, the removal of chemically adsorbed tea-polyphenols from graphene is known to be difficult and the application of centrifugation or filtration alone for the purification of graphene against tea-polyphenols is regarded to be almost technically impossible. Notably, a strategy for facile deoxygenation of tea-graphene must be established for a green and economical production of graphene to be realized. In this work, a simple purification method of graphene through the application of merely a household bleach ( Clorox®) after the pre-exfoliation in black tea has been proposed. It has been found that the carbon–oxygen (C/O) value for graphene increases from 2.7 to 8.1 while the values of C–OH, C–O–C and C=O region in the C1s spectrum of graphene decrease significantly after being purified in bleach for 5 h. The stretching and shift of C–OH, C=O and C–O–C at 3468 cm−1, 1637 cm−1 and 1008 cm−1 from IR spectrum of purified graphene seems to be in agreement with the produced data from the XPS and Raman spectroscopy. Despite the enhanced ID/IG of Raman from the hybridization of sp2 by hydroxylation, the deoxygenation of tea-graphene does not negatively affect the electrical performance since the sheet resistance was impressively reduced to 193 Ω from 2.1 kΩ. It is believed that this photo-Fenton-inspired purification strategy would assist in the washing issue of polyphenol-stabilized graphene for various future electronic applications.

식물성 오일을 이용한 바이오 항공유의 제조공정에서 탈산소 반응의 적절한 운전조건 선정을 통한 생성물 물성 최적화는 최대의 바이오항공유 수율을 얻기 위해 필수적인 요소이다. 이에 따라 팜유의 탈산소화 반응이 1 wt.% Pt/Al2O3촉매가 장입된 내경이 1인치인 고정층 반응기에서 수행되었다. 업그레이딩 공정을 통하여 수송 연료로 활용될 수 있는 액체 생성물(organic liquid product)은 가스 크로마토그래피 방법으로 그 조성을 분석하였다. 피드 내의 팜유/수소 비율과 수소 압력은 탈카르복실레이션과 수첨탈산소 반응에 영향을 주어 생성물의 조성 변화를 초래하였다. 반응 온도가 증가함에 따라 탈산소 생성물의 연속적 크래킹 반응이 촉진되어 C5~C14영역의 생성물 조성이 증가하였다. 본 연구의 결과는 팜유의 탈산소화 반응 특성의 이해 뿐 아니라 연속 공정인 수첨 업그레이딩 공정을 통한 바이오 항공유의 제조에 도움을 줄 수 있다.

Metal oxide promoted ceria-zirconia (Ce/Zr = 6/4) catalysts was applied to deoxygenation (DO) of oleic acid in batch mode at 300℃ under 1 bar of 20% H2/N2 condition. Metal oxide promoted ceria-zirconia catalysts were prepared by a co-precipitation method. As a result, Ni-Ce0.6Zr0.4O2 catalyst exhibited much higher oleic acid conversion, selectivity to C9 ~ C17 compounds (diesel fuel range), and oxygen removal efficiency than the others. This is due to the presence of free NiO species, synergy effect of nickel and Ce0.6Zr0.4O2, highest BET surface area, and the strong metal to support interaction (SMSI).

Ce(1-x)Zr(x)O2 catalysts were investigated for bio-diesel production from oleic acid using catalytic deoxygenation. In this study, deoxygenation reaction has been carried out at 300 oC under 1 bar of 20% H2/N2 pressure in batch mode. Ce(1-x)Zr(x)O2 catalysts were prepared by co-precipitation method. Ce0.6Zr0.4O2 catalyst showed the highest oleic acid conversion and C9~C17 selectivity. It has been found that the deoxygenation reaction depends strongly on the reduction property and depends partly on the crystallite size of Ce(1-x)Zr(x)O2. Thus, Ce0.6Zr0.4O2 can be selected as the most promising catalyst for deoxygenation reaction.