IRC data for a mechanistic route starting with H2O adsorption and finishing with H2 desorption from graphene

Intrinsic reaction coordinate (IRC) data regarding the interactions of water with a carbene-like active site located at the edge of a polyaromatic hydrocarbon [1–3] has been obtained using density functional theory (DFT) and the 6–31g(d) basis set as implemented in the Gaussian 16 software [4]. The data is presented as two videos (frontal and lateral mechanism views) combining four consecutive IRC calculations corresponding to the four different transition states presented on “https://doi.org/10.1016/j.carbon.2020.01.011” [3] (Figure 6, side approach). These videos provide powerful insights on two key aspects: a) the rotational process that occurs during water adsorption and b) the hydrogen gas desorption process during water gasification of carbons.


a b s t r a c t
Intrinsic reaction coordinate (IRC) data regarding the interactions of water with a carbene-like active site located at the edge of a polyaromatic hydrocarbon [1e3] has been obtained using density functional theory (DFT) and the 6e31g(d) basis set as implemented in the Gaussian 16 software [4]. The data is presented as two videos (frontal and lateral mechanism views) combining four consecutive IRC calculations corresponding to the four different transition states presented on "https://doi.org/10.1016/j.carbon. 2020.01.011" [3] (Figure 6, side approach). These videos provide powerful insights on two key aspects: a) the rotational process that occurs during water adsorption and b) the hydrogen gas desorption process during water gasification of carbons.
© 2020 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/).

Data
Two videos regarding the interactions of water with a carbene-like active site located at the edge of a polyaromatic hydrocarbon [1,2] are presented [6], H2OCarbeneSide_front.mp4 and H2OCarbeneSide.mp4. The first one shows the frontal view of the IRC sequence for the reaction mechanism of a water molecule with a carbene-like active site from the adsorption process to the H 2 desorption process. The second one presents the lateral view of the same process. Both videos share the same timing and are labelled as described in Ref. [3]. Reverse IRC parts are indicated as uphill processes, forward IRC paths are indicated as downhill processes, transition states are labelled with their corresponding activation energy in kcal/mol and frozen for 3 seconds in order to capture there characteristics; finally, intermediate structures are also labelled with a name and their relative energy with respect to the reactants.

Experimental design, materials, and methods
Forward and backward IRC calculations for four different transition states using DFT with the B3LYP functional and the 6e31g(d) basis set were calculated [4]. The temperature and pressure are 298 K and 1 atm. Forces are calculated at the first point and recalculated every five steps. The step size was the software default size.
The resulting IRC calculations correspond to an optimization in the direction of the negative vibrational frequency of the transition state. Data was calculated for as many steps as possible with a maximum of 30 on each direction. A video was generated using GaussView for each IRC. iMovie was Specifications Table   Subject Physical and Theoretical Chemistry Specific subject area Mechanism data regarding the interactions of water with a carbene-like active site located at the edge of a polyaromatic hydrocarbon (during water gasification) Type of data Value of the Data Data presents ab initio evidence of the water adsorption phenomena, which from the molecular point of view presents a rotation of the molecule as it approaches to the active site. Also, an H 2 desorption path for water gasification is presented, which requires the combination of two specific contiguous sites. This data is important for researchers studying water reactions where slow rates are seen, and where slow diffusion mechanisms might be assumed under the lack of other evidence. As an example, this might be relevant for researchers studying hydration of macromolecules such as proteins [5]. Data can be used as an ab initio evidence of special rotational features of the water molecule and also with educational purposes. The data has also an educational value, because it presents a full reaction mechanism for water gasification on a single carbene-like active site from the adsorption step to the desorption of H 2 as the first product.
then used for producing the final mechanism video. Labelling of the structures to match Figure 6 (side approach) of [3] is also added.