produced by the Haber-Bosch process, typically using fused iron as the catalyst. However, the iron-based catalyst requires harsh reaction conditions (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) and catalysts that work under mild conditions are therefore much needed. This may become more relevant in the future because as the needs for ammonia shift from fertilizer to energy, new plants operating under different conditions (lower pressure, alternate N 2 / H 2 ratios, etc.) may become necessary.In terms of the catalyst metal, ruthenium (Ru) is one of the most promising candidate elements for ammonia synthesis under mild conditions. Ru-based catalysts on carbon [3] and MgO [4] have also been extensively reported. Regarding support materials, over the most recent past few years, a number of new studies have focused on new catalysts incorporating metal hydride or electride in the support, such as 12CaO·7Al 2 O 3 :e − (C12A7:e − ), [5] [Ca 2 N]:e − , [6] CaH 2 , [7] Ca 2 NH, [8] Y 5 Si 3 , [9] LaScSi, [10] LiH, [11] and BaH 2 , [12] where all of these catalysts show high activities and unusual mechanisms. As related materials, we have recently examined BaTiO 2.5 H 0.5 and TiH 2 as a catalyst for NH 3 synthesis under Haber-Bosch conditions (400 °C, 5 MPa). [13] Titanium, being an early transition metal, was traditionally viewed as an inactive metal for catalytic NH 3 Ammonia is an attractive energy carrier for the hydrogen economy, given its high hydrogen density and ease of liquefaction. A titanate oxyhydride has recently been demonstrated that can catalyze ammonia synthesis without Ru or Fe metal, despite titanium being regarded as an inert element. Here, the synthesis activity of ammonia is examined when Ru, Fe, and Co particles are supported onto the oxyhydride BaTiO 2.5 H 0.5 . The activity of BaTiO 2.5 H 0.5 as support is significantly higher than BaTiO 3 . For example, the activity for Fe and Co increases by a factor of 70-400, making them more active than Ru/ MgO, one conventional Ru catalyst. In terms of mechanism, for Ru, H/D isotope studies show participation of lattice hydride in the catalytic cycle, while kinetic analysis shows reduced H 2 poisoning probably due to spillover. For Fe (and Co), the presence of hydride results in significantly lower activation energy and N 2 reaction order, likely due to strong electron donation from the oxyhydride. This metal-dependent support effect is further verified by N 2 isotopic exchange experiments. These perovskite-type oxyhydrides can be easily modified in terms of A-and B-site (A = Ba, B = Ti); the high potential for compositional variation and morphologies will expand the search for efficient catalysts for ammonia synthesis.

A novel atmospheric pressure plasma-initiated chemical vapor deposition (AP-PiCVD) approach toward the growth of conventional polymer layers is characterized and interpreted. A set of three methacrylate monomers (methyl, butyl, and glycidyl methacrylate) were investigated using ultrashort plasma discharges (ca. 100 ns) pulsed at various frequencies, covering a range of duty cycle from 0.1% to 0.000 316%. An unprecedented weight-average molar mass of 94 000 g mol −1 coupled to an outstanding thin film conformality and an excellent chemical functionalities retention was achieved for the best deposition conditions. Insights into the growth mechanisms in AP-PiCVD and their dependence on the monomer's intrinsic properties are provided.

A comprehensive mass-spectrometry study of a set of poly(alkyl acrylate) layers synthesized by atmospheric pressure plasma-initiated chemical vapor deposition (AP-PiCVD) is provided. High-resolution mass spectrometry investigations demonstrate that exposure of the alkyl acrylate monomers to ultra-short and lowfrequency plasma pulses produces a defined number of radical and neutral fragments, which can play both the roles of polymerization initiation or termination groups. Further inquiries illustrate the competition between a conventional free-radical polymerization pathway and plasma-polymerization. On the basis of the massspectrometry observations and the bond dissociation energies calculated by density functional theory, guidelines are made to select appropriate AP-PiCVD monomers. K E Y W O R D Satmospheric-plasma CVD, conventional polymerization, high-resolution mass-spectrometry, nanopulsed discharge, polymerization mechanisms 1 | INTRODUCTION In many synthesis reactions, plasma provides a convenient alternative to thermal heating [1] or chemical reactants. [2] Noticeably, plasma-enhanced chemical vapor deposition (PECVD) processes can lead to the simultaneous lowtemperature synthesis and deposition of crystalline metal oxide thin films on polymer substrates [3] or ensure the "polymerization" of chemically non-polymerizable precursors. [4,5] The PECVD of many inorganic and organic materials has already been reported and the fine-tuning of the PECVD parameters, e.g., the composition of the plasma gas and the plasma excitation mode, can trigger a wide range of reactions, including the reduction of metal salts, [6] the oxidative polymerization of aromatic compounds, [2] and the free-radical polymerization of vinylene monomers. [7] Nevertheless, due to the intrinsic nature of plasmas, consisting of many reactive species with a wide energy range, a nonnegligible number of side reactions occurs. [2] As a consequence to the non-specificity of plasma-induced reactions and the sensitivity of the organic bonds, the chemical structure of monomers is only partially retained and the resulting PECVD This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

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