No abstract

Reverse water gas shift on the basis of chemical looping technology provides a viable method for efficiently converting CO2 to CO for hydrocarbons at moderate temperature (<750 °C). However, the commonly available oxygen carrier materials are insufficiently active because of the degrading effect at relatively low temperatures. In this paper, we present several Co, Mn codoped ferrites in search of oxygen carrier materials as highly active redox materials for a midtemperature chemical looping CO2 splitting process. The results show that up to ∼142.3 μmol·g–1·min–1 of CO production rate and ∼8.8 mmol·g–1 of CO yield are achieved by Mn0.2Co0.8Fe2O4 at 650 °C. The production rate and yield of CO of the codoped ferrites during the CO2 splitting process are comparable to those of the state-of-the-art perovskites which commonly contain rare-metal elements.

Papillary thyroid carcinoma (PTC) is an aggressive histological subtype of thyroid carcinoma (THCA), whose occurrence rate is high. The participation of long noncoding RNAs in the pathologies of cancers has attracted significant attention during the past decades. The purpose of the current study is to investigate the role of NR2F1 antisense RNA 1 (NR2F1‐AS1) in PTC. The expression of NR2F1 in THCA samples was analyzed by bioinformatics tool gene expression profiling interactive analysis. Levels of NR2F1‐AS1, microRNA‐423‐5p (miR‐423‐5p), and SRY‐box 12 (SOX12) were evaluated by a quantitative reverse transcription‐polymerase chain reaction and Western blot. The impact of NR2F1‐AS1 on PTC cell proliferation and invasion was assessed by Cell Counting Kit‐8, EdU, and Transwell invasion assays. The interactions among NR2F1‐AS1, miR‐423‐5p, and SOX12 were determined by RNA immunoprecipitation and luciferase reporter assays. Consequently, we found that NR2F1‐AS1 and SOX12 levels were elevated in PTC, whereas miR‐423‐5p was downregulated in PTC cells. Functionally, NR2F1‐AS1 silence led to reduced proliferation and invasion of PTC cells. Mechanistically, NR2F1‐AS1 interacted with miR‐423‐5p to induce SOX12 expression in PTC cells. In conclusion, the present study firstly stated that NR2F1‐AS1 regulated miR‐423‐5p/SOX12 to promote proliferation and invasion of PTC, indicating NR2F1‐AS1 as a potential novel target for the molecular‐targeted therapy of PTC.

CO2 photoreduction is a promising avenue to alleviate climate change and energy shortage, and highly active and selective photocatalysts have been pursued. Discrete metal–organic cages (MOCs) with tunable structures and dispersion not only render integration of multiple functional moieties but also facilitate the accessibility of catalytic sites, yet the studies of MOCs on CO2 reduction are still underexplored. Herein, a single molecular cage of the Ir­(III) complex-decorated Zr-MOC (IrIII-MOC-NH2) is proposed for CO2 photoreduction. IrIII-MOC-NH2 shows high reactivity and selectivity in converting CO2 into CO under visible light. The selectivity is of 99.5% and the turnover frequency reaches ∼120 h–1 which is 3.4-fold higher than that of bulk IrIII-MOC-NH2 and two orders of magnitude higher than that of the classical metal–organic framework counterpart (IrIII-Uio-67-NH2). The apparent quantum yield is up to 6.71% that ranks the highest among the values reported for crystalline porous materials. Moreover, aggregation-induced deactivation of the Ir­(III) complex is restrained after incorporating into MOC-NH2. The density functional theory calculations and dedicated experiments including cyclic voltammetry, mass spectrometry and in situ IR show that the Ir­(III) complex is the catalytic center, and −NH2 in the framework plays the synergetic role in the stabilization of the transition state and CO2 adducts.

The chemical looping process is promising for CO2 conversion because of the much higher CO2 conversion efficiency than the photocatalytic and electrocatalytic processes. Conventional oxygen carriers have to include a high content of inert support, typically Al2O3, to avoid sintering, thus leading to a trade-off between reactivity and stability. Here, we propose the use of ion-conductive Gd x Ce2–x O2−δ (GDC) to prepare the supported oxygen carriers. The resulting Fe2O3/GDC materials achieve both high reactivity and stability. Fe2O3/Gd0.3Ce1.7O2−δ shows high CO productivity (∼10.79 mmol·g–1) and CO production rate (∼0.77 mmol·g–1·min–1), which are twofold higher than that of Fe2O3/Al2O3. The performance remains stable even after 30 cycles. The mechanism study confirmed the rate-limiting role of the oxygen-ion conductivity, and the GDC support enhanced the oxygen-ion conductivity of oxygen carriers during the redox reactions, thus leading to improved CO2 splitting performance. A roughly linear relationship between the oxygen-ion conductivity and CO2 yield is also obtained and verified in our testing conditions. This relation can be used to predict and select oxygen carriers with high CO2 splitting performance.

No abstract

No abstract

No abstract