Additionally, we investigated binary and ternary compounds in CO 2 RR but exclusively considering cations. This allowed us to gain insights into the metal alloys employed, as shown in Figure (c) and 5(f). In Figure (c), we can observe the prevalence of Cu as the metallic element that most appear in alloys, followed by Ni and Pd. Numerous articles in the literature have explored the alloying of Cu with different metals to modulate the faradaic efficiency (FE) and applied potential for CO 2 RR . Nevertheless, the highest frequency scores occur for NiFe and PdAu alloys. NiFe catalysts are commonly utilized in the methanation reaction, to hydrogenate carbon monoxide into methane . Papers in our corpus, however, mention the application of this material for both CORR and CO 2 RR. AuPd alloys, on the other hand, are also known compositions for CO 2 RR . One of the articles in our corpus mentions that "Pd 1 Au 24 can convert CO 2 to CO with 100% faradaic efficiency" at applied potentials ranging from -0.6 to -1.2V vs RHE . However, we are surprised these alloys have a higher citation score than any Cu-based materials. Another interesting result in Figure (f) is that copper only occurs in a single composition, NiFeCu, despite having a lower score than CoAlLa and CoNiPt. Among the identified sentences, CoAlLa is predominantly mentioned as a layered double hydroxide (LDH). These structures are cited in one of the reviewed articles as a strategy for designing catalysts for CO 2 RR. However, it is worth noticing that the papers in our corpus that mention CoAlLa were all published after 2019. Conversely, publications on PtCoNi alloys are slightly older, with the most recent one published in 2020, and all of them primarily employed PtCoNi alloys for the hydrogen evolution reaction (HER).