Boosting the ammonia synthesis activity of ceria-supported Ru catalysts achieved through trace Pr addition.

The amount of dopant used in conventional cases for improving catalytic performance is higher than 5%. In this work, a strategy to enhance the ammonia synthesis performance of a Ru/CeO2 catalyst by using trace Pr (0.1 mol%) is reported. Owing to the improvement of oxygen defects, Ce3+ concentration and interfaced Ru species, the hydrogen adsorption was enhanced, and the desorption of hydrogen species would be promoted. As a result, Ru/CeO2 with 0.1 mol% Pr shows 1.4 times higher ammonia synthesis rate and excellent stability compared to Ru/CeO2 or the sample with high Pr loading (50 mol% Pr). This study provides a new idea for the design of high-efficiency ammonia synthesis catalysts.

Enhanced ammonia synthesis activity of carbon-supported Mo catalyst by Mo carburization.

It is urgent to develop new efficient ammonia synthesis catalysts using non-precious metals. Herein, the Mo2C species is introduced into a carbon-supported Mo catalyst by in situ carburization of a carbon-supported Mo catalyst in H2. In combination with the presence of the Mo2C phase as well as the enhancement of the graphitization degree of carbon and the amount of the low-valent Mo species, the migration and the exchange of the adsorbed species with the gaseous species are accelerated. As a result, the catalyst with carbonization treatment shows higher ammonia synthesis activity than the sample without carbonization, and the ill effect of the poisoning of reagent gases also is alleviated.

Advances in Multi-Omics Study of Prognostic Biomarkers of Diffuse Large B-Cell Lymphoma.

As the most common subtype of non-Hodgkin's lymphoma, diffuse large B-cell lymphoma (DLBCL) is characterized by a huge degree of clinical and prognostic heterogeneity. Currently, there is an urgent need for highly specific and sensitive biomarkers to predict the therapeutic response of DLBCL and assess which patients can benefit from systemic chemotherapy to help develop more precise therapeutic regimens for DLBCL. Systems biology (holistic study of diseases) is more comprehensive in quantifying and identifying biomarkers, helps addressing major biological problems, and possesses high accuracy and sensitivity. In this article, we provide an overview of research advances in DLBCL prognostic biomarkers made using the multi-omics approach of genomics, transcriptomics, epigenetics, proteomics, metabonomics, radiomics, and the currently developing single-cell technologies.

Enhanced ammonia synthesis performance of ceria-supported Ru catalysts via introduction of titanium.

The spatial arrangements of Ti species would affect the electronic metal-support interactions and the proportion of Ce3+ sites for ceria-supported Ru catalysts. Ti-Surface-loaded CeO2 supported Ru catalysts exhibited excellent ammonia synthesis activity, which is attributed to a larger proportion of Ru metal, more electrons of Ru species and better adsorption ability of hydrogen and nitrogen.

Zeolite-seed-directed Ru nanoparticles highly resistant against sintering for efficient nitrogen activation to ammonia.

To stabilize Ru nanoparticles against sintering is an urgent problem in the utilization of Ru-based catalysts for NH3 synthesis. In the present study, we used Ru-containing ZSM-5 as seeds to crystallize ZSM-5, and the resulted Ru@ZSM-5 catalyst is highly resistant against Ru sintering. According to the results of diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) and transmission electron microscopy (TEM) analyses, the average size of Ru nanoparticles is around 3.6 nm, which is smaller than that of Ru/ZSM-5-IWI prepared by incipient wetness impregnation. In NH3 synthesis (N2:H2 = 1:3) at 400 °C and 1 MPa, Ru@ZSM-5 displays a formation rate of 5.84 mmolNH3 gcat-1 h-1, which is much higher than that of Ru/ZSM-5-IWI (2.13 mmolNH3 gcat-1 h-1). According to the results of TEM, N2-temperature-programmed desorption (N2-TPD), X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) studies, it is deduced that the superior performance of Ru@ZSM-5 is attributable to the small particle size and the ample existence of metallic Ru0 sites. This method of zeolite encapsulation is a feasible way to stabilize Ru nanoparticles for NH3 synthesis.

Strong metal-support interactions of Co-based catalysts facilitated by dopamine for highly efficient ammonia synthesis: in situ XPS and XAFS spectroscopy coupled with TPD studies.

We report a new strategy for strengthening metal-support interaction and stabilizing Co nanoparticles at high temperature. Through the use of dopamine and removal of carbon layers by thermal N2 treatment, ceria-based Co catalysts that are efficient and highly stable for ammonia synthesis can be obtained. The ammonia synthesis rate at 425 °C and 1 MPa is enhanced from 3.81 mmolNH3 gcat-1 h-1 over Co/CeO2 to 19.12 mmolNH3 gcat-1 h-1 over a dopamine-mediated catalyst. The superior catalytic performances of the dopamine-mediated Co/CeO2 catalyst are associated with smaller crystalline size, stronger metal-support interaction and lower N2 activation energy.