Photoinduced Precise Synthesis of Diatomic Ir1 Pd1 -In2 O3 for CO2 Hydrogenation to Methanol via Angstrom-Scale-Distance Dependent Synergistic Catalysis.

The atomically dispersed metal catalysts with full atomic utilization and well-defined site structure hold great promise for various catalytic reactions. However, the single metallic site limits the comprehensive reaction performance in most reactions. Here, we demonstrated a photo-induced neighbour-deposition strategy for the precise synthesis of diatomic Ir1 Pd1 on In2 O3 applied for CO2 hydrogenation to methanol. The proximity synergism between diatomic sites enabled a striking promotion in both CO2 conversion (10.5 %) and methanol selectivity (97 %) with good stability of 100 h run. It resulted in record-breaking space-time yield to methanol (187.1 gMeOH gmetal -1  hour-1 ). The promotional effect mainly originated from stronger CO2 adsorption on Ir site with assistance of H-spillover from Pd site, thus leading to a lower energy barrier for *HCOO pathway. It was confirmed that this synergistic effect strongly depended on the dual-site distance in an angstrom scale, which was attributed to weaker *H spillover and less electron transfer from Pd to Ir site as the Pd-to-Ir distance increased. The average dual-site distance was evaluated by our firstly proposed photoelectric model. Thus, this study introduced a pioneering strategy to precisely synthesize homonuclear/heteronuclear diatomic catalysts for facilitating the desired reaction route via diatomic synergistic catalysis.

Ti-doped CeO2 Stabilized Single-Atom Rhodium Catalyst for Selective and Stable CO2 Hydrogenation to Ethanol.

Development of effective and stable catalysts for CO2 hydrogenation into ethanol remains a challenge. Herein, we report that Rh1 /CeTiOx single-atom catalyst constructed by embedding monoatomic Rh onto Ti-doped CeO2 support has shown a super high ethanol selectivity (≈99.1 %), record-breaking turnover frequency (493.1 h-1 ), and outstanding stability. Synergistic effects of Ti-doption and monoatomic Rh contribute to this excellent catalytic performance by firstly facilitating oxygen vacancies formation to generate oxygen-vacancy-Rh Lewis-acid-base pairs, which favor CO2 adsorption and activation, cleavage of C-O bonds in CHx OH* and COOH* into CHx * and CO* species, subsequent C-C coupling and hydrogenation into ethanol, and secondly generating strong Rh-O bond by Ti-doping-induced crystal reconstruction, which contributes to striking stability. This work highlights the importance of support elaborating regulation for single-atom catalyst design to substantially improve the catalytic performance.

Upcycling of Cr-Containing Sulfate Waste into Efficient FeCrO3/Fe2O3 Catalysts for CO2 Hydrogenation Reaction.

Upcycling Cr-containing sulfate waste into catalysts for CO2 hydrogenation reaction benefits both pollution mitigation and economic sustainability. In this study, FeCrO3/Fe2O3 catalysts were successfully prepared by a simple hydrothermal method using Cr-containing sodium sulfate (Cr-SS) as a Cr source for efficient conversion and stable treatment of Cr. The removal rate of Cr in Cr-SS can reach 99.9% at the optimized hydrothermal conditions. When the synthesized catalysts were activated and used for the CO2 hydrogenation reaction, a 50% increase in CO2 conversion was achieved compared with the catalyst prepared by impregnation with a comparable amount of Cr. According to the extraction and risk assessment code (RAC) of the Reference Office of the European Community Bureau (BCR), the synthesized FeCrO3/Fe2O3 is risk-free. This work not only realizes the detoxification of the Cr-SS but transfers Cr into stable FeCrO3 for application in a catalytic field, which provides a strategy for the harmless disposal and resource utilization of Cr-containing hazardous waste.

Study on detection of mutation DNA fragment in gastric cancer by restriction endonuclease fingerprinting with capillary electrophoresis.

The DNA fragment detection focusing technique has further enhanced the sensitivity and information of DNA targets. The DNA fragment detection method was established by capillary electrophoresis with laser-induced fluorescence detection and restriction endonuclease chromatographic fingerprinting (CE-LIF-REF) in our experiment. The silica capillary column was coated with short linear polyarclarylamide (SLPA) using nongel sieving technology. The excision product of various restricted enzymes of DNA fragments was obtained by REF with the molecular biology software Primer Premier 5. The PBR322/BsuRI DNA marker was used to establish the optimization method. The markers were focused electrophoretically and detected by CE-LIF. The results demonstrate that the CE-LIF-REF with SLPA can improve separation, sensitivity and speed of analysis. This technique may be applied to analysis of the excision product of various restricted enzymes of prokaryotic plasmid (pIRES2), eukaryote plasmid (pcDNA3.1) and the PCR product of codon 248 region of gastric cancer tissue. The results suggest that this method could very sensitively separate the excision products of various restricted enzymes at a much better resolution than the traditional agarose electrophoresis.

High-Efficiency Photo-Thermo-Electric System with Waste Heat Utilization and Energy Storage.

In a photo-thermo-electric system, solar energy is first converted into heat and then into electrical energy, which has attracted much attention. However, the heat of the cold side of a thermoelectric generator (TEG) is generally removed by an air-cooling or water-cooling technology without being fully utilized, resulting in a low solar energy utilization efficiency. Here, we designed an integrated system composed of a photo-thermo-electric conversion part and a waste energy collection part. In this system, one carbon foam (CF) doped with PPy and PEG is used as a layer for photothermal conversion and energy storage, and the other CF─where one side was hydrophobically modified─is used for the storage of cooling water and the recovery of waste heat. The two CF layers contact the hot and cold sides of TEG, respectively. With the system, solar energy can be converted into heat and then electricity for TEG. On the other hand, waste heat can be utilized for seawater desalination by the process of water evaporation. In addition, the integrated system can work sustainably under intermittent light conditions. With the recovery of waste heat, the solar energy utilization efficiency in this system is greatly increased to as much as 86%.

CH4 conversion over Ni/HZSM-5 catalyst in the absence of oxygen: decomposition or dehydroaromatization?

The different chemical states and locations of Ni species in HZSM-5 result in different directions of CH4 reaction. Supported Ni clusters caused complete CH4 decomposition, while Ni-exchanged sites anchored at Brønsted acid sites, can appropriately activate CH4 into CHx species which are important precursors to produce aromatics. This study suggests a catalyst construction strategy for selective conversion of CH4 towards value-added chemicals by placing active metal at specific sites.

Investigation on converting 1-butene and ethylene into propene via metathesis reaction over W-based catalysts.

Supported W catalysts were extensively investigated for the conversion of 1-butene and ethylene into propene by metathesis reaction. The performance of catalysts was compared by using unsupported WO3, pure SBA-15, supported W/SBA-15 with different W loadings, varied calcination temperatures, and by changing the pretreatment gas atmosphere. The above catalytic results could be employed to deduce the reaction mechanism combined with characterization techniques such as BET, XRD, UV-vis DRS, Raman, pyridine-IR, XPS, and H2-TPR. In this study, over the investigated W/SBA-15 catalysts, the results showed that the silanol group (Si-OH) in SBA-15 could act as a weak Brønsted acid site for 1-butene isomerization. However, the metathesis reaction was catalyzed by W-carbene species. The initially formed W-carbenes (W[double bond, length as m-dash]CH-CH3) as active sites were derived from the partially reduced isolated tetrahedral WO x species which contained W[double bond, length as m-dash]O or W-OH bonds in W5+ species as corresponding Lewis or Brønsted acid sites. Furthermore, the W/SBA-15 being pretreated by H2O led to a complete loss of the metathesis activity. This was mainly due to the sintering of isolated WO x species to form an inactive crystalline WO3 phase as demonstrated by XRD patterns. On the other hand, the reduction of WO x species remarkably suppressed by H2O pretreatment was also responsible for the metathesis deactivation. This study provides molecular level mechanisms for the several steps involved in the propene production, including 1-butene isomerization, W-carbene formation, and metathesis reaction.