As an expert-curated resource, the CAS content is utilized here for the quantitative analysis of publications against variables including time, country/region, research area, and substance details. We have used this resource to investigate the recent progress towards nitrogen reduction reaction (NRR) with an emphasis on electrocatalysts and photocatalysts. The recent research landscape in this area can be visualized in many ways; we begin by presenting the most commonly co-occurring concepts found to be important within each respective study in a clustered network diagram generated by VOSviewer (Fig. ). From 2001 to 2021, electrochemical reduction and related concepts were among the most frequently occurring concepts we have found associated with green ammonia and NRR, with "photocatalysts" occurring less frequently. The concept "photocatalysts" has significant overlap with several nanomaterialrelated concepts. The top three nanomaterial-related concepts co-occurring with "photocatalysts" are "nanoparticles", "nanosheets", and "nanocomposites." We also see that the "hydrogen evolution reaction" concept is indexed at a significant rate. This finding underscores that studies of NRR catalysts in the presence of water must consider the competing water reduction reaction to optimize ammonia production. Finally, the inclusion of a cluster of surface-oriented concepts such as "surface structure", "surface area", and "pore size distribution" shows the relevance of surface phenomena in catalyst design.